diff --git a/config.json b/config.json
index b830ecfba7..1ea31524c4 100644
--- a/config.json
+++ b/config.json
@@ -17,15 +17,20 @@
       "auto_approve": true,
       "unlocked_by": null,
       "difficulty": 1,
-      "topics": ["strings"]
+      "topics": [
+        "strings"
+      ]
     },
     {
-      "slug": "reverse-string",
-      "uuid": "14395318-c7b9-11e7-abc4-cec278b6b50a",
-      "core": false,
+      "slug": "two-fer",
+      "uuid": "57f02d0e-7b75-473b-892d-26a7d980c4ce",
+      "core": true,
       "unlocked_by": null,
       "difficulty": 1,
-      "topics": ["strings"]
+      "topics": [
+        "optional_values",
+        "strings"
+      ]
     },
     {
       "slug": "leap",
@@ -33,23 +38,41 @@
       "core": true,
       "unlocked_by": null,
       "difficulty": 1,
-      "topics": ["control_flow_if_else_statements", "integers"]
+      "topics": [
+        "control_flow_if_else_statements",
+        "integers"
+      ]
     },
     {
-      "slug": "bob",
-      "uuid": "da00f894-dbc8-485e-adba-a79d5ebee3ad",
+      "slug": "gigasecond",
+      "uuid": "b7116dfb-1107-4546-9f95-f15acdb6f6a4",
       "core": true,
       "unlocked_by": null,
       "difficulty": 1,
-      "topics": ["control_flow_if_else_statements", "strings"]
+      "topics": [
+        "dates"
+      ]
     },
     {
-      "slug": "sum-of-multiples",
-      "uuid": "d985d4a9-1a2b-4bb1-ad08-961b8d36ee2e",
+      "slug": "series",
+      "uuid": "9ca46617-4995-45cc-a2dd-b8630eaa288b",
       "core": true,
       "unlocked_by": null,
       "difficulty": 1,
-      "topics": ["arrays", "math", "transforming"]
+      "topics": [
+        "arrays",
+        "strings"
+      ]
+    },
+    {
+      "slug": "space-age",
+      "uuid": "612f058b-c6d9-4c97-913a-eeeb59ef61e1",
+      "core": true,
+      "unlocked_by": null,
+      "difficulty": 1,
+      "topics": [
+        "floating_point_numbers"
+      ]
     },
     {
       "slug": "raindrops",
@@ -57,15 +80,21 @@
       "core": true,
       "unlocked_by": null,
       "difficulty": 2,
-      "topics": ["filtering", "strings"]
+      "topics": [
+        "filtering",
+        "strings"
+      ]
     },
     {
-      "slug": "two-fer",
-      "uuid": "57f02d0e-7b75-473b-892d-26a7d980c4ce",
+      "slug": "bob",
+      "uuid": "da00f894-dbc8-485e-adba-a79d5ebee3ad",
       "core": true,
       "unlocked_by": null,
       "difficulty": 1,
-      "topics": ["optional_values", "strings"]
+      "topics": [
+        "control_flow_if_else_statements",
+        "strings"
+      ]
     },
     {
       "slug": "nucleotide-count",
@@ -73,61 +102,43 @@
       "core": true,
       "unlocked_by": null,
       "difficulty": 2,
-      "topics": ["dictionaries", "strings"]
+      "topics": [
+        "dictionaries",
+        "strings"
+      ]
     },
     {
-      "slug": "accumulate",
-      "uuid": "3c0563dc-665a-45b4-9b29-f133e235efd0",
+      "slug": "allergies",
+      "uuid": "2ac228d8-7bf0-4946-8352-6541df02c0a2",
       "core": true,
       "unlocked_by": null,
-      "difficulty": 2,
-      "topics": ["extension_methods", "sequences", "transforming"]
+      "difficulty": 4,
+      "topics": [
+        "bitwise_operations",
+        "filtering"
+      ]
     },
     {
-      "slug": "grade-school",
-      "uuid": "ec1cc254-8e66-40d0-87bf-971d54c541c4",
+      "slug": "binary-search",
+      "uuid": "f92ff94a-73e6-41cb-a376-835c2368b358",
       "core": true,
       "unlocked_by": null,
-      "difficulty": 2,
-      "topics": ["lists", "sorting"]
-    },
-    {
-      "slug": "collatz-conjecture",
-      "uuid": "c4efbf8a-8e76-4700-807d-830a4938f4d0",
-      "core": false,
-      "unlocked_by": "sum-of-multiples",
-      "difficulty": 2,
+      "difficulty": 3,
       "topics": [
-        "algorithms",
-        "control_flow_conditionals",
-        "control_flow_loops",
-        "integers",
-        "math"
+        "arrays",
+        "searching"
       ]
     },
     {
-      "slug": "armstrong-numbers",
-      "uuid": "8150604d-4cdc-414a-a523-dd65ac536f0e",
-      "core": false,
-      "unlocked_by": "sum-of-multiples",
-      "difficulty": 2,
-      "topics": ["math"]
-    },
-    {
-      "slug": "rational-numbers",
-      "uuid": "9ae7f7ed-75d8-4d03-967c-53846634ae07",
-      "core": false,
-      "unlocked_by": "leap",
-      "difficulty": 4,
-      "topics": ["math"]
-    },
-    {
-      "slug": "kindergarten-garden",
-      "uuid": "b7458404-2534-4ed8-8350-7060fa4b5786",
+      "slug": "grade-school",
+      "uuid": "ec1cc254-8e66-40d0-87bf-971d54c541c4",
       "core": true,
       "unlocked_by": null,
-      "difficulty": 3,
-      "topics": ["enumerations", "parsing"]
+      "difficulty": 2,
+      "topics": [
+        "lists",
+        "sorting"
+      ]
     },
     {
       "slug": "clock",
@@ -135,23 +146,21 @@
       "core": true,
       "unlocked_by": null,
       "difficulty": 3,
-      "topics": ["classes", "structural_equality"]
+      "topics": [
+        "classes",
+        "structural_equality"
+      ]
     },
     {
-      "slug": "binary-search",
-      "uuid": "f92ff94a-73e6-41cb-a376-835c2368b358",
+      "slug": "kindergarten-garden",
+      "uuid": "b7458404-2534-4ed8-8350-7060fa4b5786",
       "core": true,
       "unlocked_by": null,
       "difficulty": 3,
-      "topics": ["arrays", "searching"]
-    },
-    {
-      "slug": "allergies",
-      "uuid": "2ac228d8-7bf0-4946-8352-6541df02c0a2",
-      "core": true,
-      "unlocked_by": null,
-      "difficulty": 4,
-      "topics": ["bitwise_operations", "filtering"]
+      "topics": [
+        "enumerations",
+        "parsing"
+      ]
     },
     {
       "slug": "saddle-points",
@@ -159,7 +168,11 @@
       "core": true,
       "unlocked_by": null,
       "difficulty": 4,
-      "topics": ["arrays", "matrices", "tuples"]
+      "topics": [
+        "arrays",
+        "matrices",
+        "tuples"
+      ]
     },
     {
       "slug": "markdown",
@@ -167,7 +180,11 @@
       "core": true,
       "unlocked_by": null,
       "difficulty": 5,
-      "topics": ["parsing", "refactoring", "transforming"]
+      "topics": [
+        "parsing",
+        "refactoring",
+        "transforming"
+      ]
     },
     {
       "slug": "book-store",
@@ -175,39 +192,111 @@
       "core": true,
       "unlocked_by": null,
       "difficulty": 5,
-      "topics": ["recursion"]
+      "topics": [
+        "recursion"
+      ]
     },
     {
-      "slug": "gigasecond",
-      "uuid": "b7116dfb-1107-4546-9f95-f15acdb6f6a4",
+      "slug": "reverse-string",
+      "uuid": "14395318-c7b9-11e7-abc4-cec278b6b50a",
       "core": false,
       "unlocked_by": null,
       "difficulty": 1,
-      "topics": ["dates"]
+      "topics": [
+        "strings"
+      ]
     },
     {
-      "slug": "rna-transcription",
-      "uuid": "440b0b23-220d-4706-98f0-9a89fce85acb",
+      "slug": "sum-of-multiples",
+      "uuid": "d985d4a9-1a2b-4bb1-ad08-961b8d36ee2e",
       "core": false,
-      "unlocked_by": null,
+      "unlocked_by": "series",
       "difficulty": 1,
-      "topics": ["strings", "transforming"]
+      "topics": [
+        "arrays",
+        "math",
+        "transforming"
+      ]
     },
     {
-      "slug": "space-age",
-      "uuid": "612f058b-c6d9-4c97-913a-eeeb59ef61e1",
+      "slug": "high-scores",
+      "uuid": "f52d9be9-7044-4001-8678-dcae91a8d7f3",
+      "core": false,
+      "unlocked_by": "series",
+      "difficulty": 1,
+      "topics": [
+        "lists",
+        "strings"
+      ]
+    },
+    {
+      "slug": "accumulate",
+      "uuid": "3c0563dc-665a-45b4-9b29-f133e235efd0",
+      "core": false,
+      "unlocked_by": "series",
+      "difficulty": 2,
+      "topics": [
+        "extension_methods",
+        "sequences",
+        "transforming"
+      ]
+    },
+    {
+      "slug": "collatz-conjecture",
+      "uuid": "c4efbf8a-8e76-4700-807d-830a4938f4d0",
+      "core": false,
+      "unlocked_by": "gigasecond",
+      "difficulty": 2,
+      "topics": [
+        "algorithms",
+        "control_flow_conditionals",
+        "control_flow_loops",
+        "integers",
+        "math"
+      ]
+    },
+    {
+      "slug": "armstrong-numbers",
+      "uuid": "8150604d-4cdc-414a-a523-dd65ac536f0e",
+      "core": false,
+      "unlocked_by": "space-age",
+      "difficulty": 2,
+      "topics": [
+        "math"
+      ]
+    },
+    {
+      "slug": "rational-numbers",
+      "uuid": "9ae7f7ed-75d8-4d03-967c-53846634ae07",
+      "core": false,
+      "unlocked_by": "space-age",
+      "difficulty": 4,
+      "topics": [
+        "math"
+      ]
+    },
+    {
+      "slug": "rna-transcription",
+      "uuid": "440b0b23-220d-4706-98f0-9a89fce85acb",
       "core": false,
       "unlocked_by": null,
       "difficulty": 1,
-      "topics": ["floating_point_numbers"]
+      "topics": [
+        "strings",
+        "transforming"
+      ]
     },
     {
       "slug": "difference-of-squares",
       "uuid": "5554c048-0de3-4a85-b043-7577f429cba4",
       "core": false,
-      "unlocked_by": "leap",
+      "unlocked_by": "series",
       "difficulty": 1,
-      "topics": ["control_flow_loops", "integers", "math"]
+      "topics": [
+        "control_flow_loops",
+        "integers",
+        "math"
+      ]
     },
     {
       "slug": "hamming",
@@ -215,7 +304,10 @@
       "core": false,
       "unlocked_by": "hello-world",
       "difficulty": 2,
-      "topics": ["filtering", "strings"]
+      "topics": [
+        "filtering",
+        "strings"
+      ]
     },
     {
       "slug": "grains",
@@ -223,7 +315,9 @@
       "core": false,
       "unlocked_by": "leap",
       "difficulty": 2,
-      "topics": ["integers"]
+      "topics": [
+        "integers"
+      ]
     },
     {
       "slug": "pangram",
@@ -231,7 +325,9 @@
       "core": false,
       "unlocked_by": "hello-world",
       "difficulty": 2,
-      "topics": ["strings"]
+      "topics": [
+        "strings"
+      ]
     },
     {
       "slug": "etl",
@@ -239,15 +335,22 @@
       "core": false,
       "unlocked_by": "nucleotide-count",
       "difficulty": 2,
-      "topics": ["dictionaries", "lists", "transforming"]
+      "topics": [
+        "dictionaries",
+        "lists",
+        "transforming"
+      ]
     },
     {
       "slug": "phone-number",
       "uuid": "5675771e-1a46-40bd-8923-f6e09642cc0c",
       "core": false,
-      "unlocked_by": "sum-of-multiples",
+      "unlocked_by": "gigasecond",
       "difficulty": 3,
-      "topics": ["parsing", "transforming"]
+      "topics": [
+        "parsing",
+        "transforming"
+      ]
     },
     {
       "slug": "strain",
@@ -255,15 +358,20 @@
       "core": false,
       "unlocked_by": "raindrops",
       "difficulty": 3,
-      "topics": ["filtering", "sequences"]
+      "topics": [
+        "filtering",
+        "sequences"
+      ]
     },
     {
       "slug": "scrabble-score",
       "uuid": "89c42da3-72a6-423d-a9c7-7caccbd9b1e6",
       "core": false,
-      "unlocked_by": "sum-of-multiples",
+      "unlocked_by": "gigasecond",
       "difficulty": 3,
-      "topics": ["transforming"]
+      "topics": [
+        "transforming"
+      ]
     },
     {
       "slug": "proverb",
@@ -271,7 +379,10 @@
       "core": false,
       "unlocked_by": "raindrops",
       "difficulty": 3,
-      "topics": ["algorithms", "strings"]
+      "topics": [
+        "algorithms",
+        "strings"
+      ]
     },
     {
       "slug": "robot-name",
@@ -279,15 +390,23 @@
       "core": false,
       "unlocked_by": "hello-world",
       "difficulty": 3,
-      "topics": ["classes", "randomness", "strings"]
+      "topics": [
+        "classes",
+        "randomness",
+        "strings"
+      ]
     },
     {
       "slug": "protein-translation",
       "uuid": "75a2d5f0-5f5e-46a3-9dd2-3da415690e18",
       "core": false,
-      "unlocked_by": "two-fer",
+      "unlocked_by": "series",
       "difficulty": 3,
-      "topics": ["lists", "strings", "transforming"]
+      "topics": [
+        "lists",
+        "strings",
+        "transforming"
+      ]
     },
     {
       "slug": "error-handling",
@@ -295,7 +414,9 @@
       "core": false,
       "unlocked_by": "bob",
       "difficulty": 3,
-      "topics": ["exception_handling"]
+      "topics": [
+        "exception_handling"
+      ]
     },
     {
       "slug": "perfect-numbers",
@@ -303,15 +424,21 @@
       "core": false,
       "unlocked_by": "leap",
       "difficulty": 3,
-      "topics": ["integers", "math"]
+      "topics": [
+        "integers",
+        "math"
+      ]
     },
     {
       "slug": "triangle",
       "uuid": "5b1713c7-1597-4e67-ac97-f305b207bc38",
       "core": false,
-      "unlocked_by": "leap",
+      "unlocked_by": "space-age",
       "difficulty": 3,
-      "topics": ["enumerations", "integers"]
+      "topics": [
+        "enumerations",
+        "integers"
+      ]
     },
     {
       "slug": "beer-song",
@@ -319,7 +446,10 @@
       "core": false,
       "unlocked_by": "raindrops",
       "difficulty": 3,
-      "topics": ["algorithms", "strings"]
+      "topics": [
+        "algorithms",
+        "strings"
+      ]
     },
     {
       "slug": "sieve",
@@ -327,7 +457,10 @@
       "core": false,
       "unlocked_by": "raindrops",
       "difficulty": 3,
-      "topics": ["filtering", "math"]
+      "topics": [
+        "filtering",
+        "math"
+      ]
     },
     {
       "slug": "queen-attack",
@@ -335,7 +468,9 @@
       "core": false,
       "unlocked_by": "clock",
       "difficulty": 3,
-      "topics": ["classes"]
+      "topics": [
+        "classes"
+      ]
     },
     {
       "slug": "robot-simulator",
@@ -343,7 +478,10 @@
       "core": false,
       "unlocked_by": "clock",
       "difficulty": 3,
-      "topics": ["classes", "enumerations"]
+      "topics": [
+        "classes",
+        "enumerations"
+      ]
     },
     {
       "slug": "isogram",
@@ -351,15 +489,21 @@
       "core": false,
       "unlocked_by": "two-fer",
       "difficulty": 3,
-      "topics": ["filtering", "strings"]
+      "topics": [
+        "filtering",
+        "strings"
+      ]
     },
     {
       "slug": "secret-handshake",
       "uuid": "1ad236a9-7035-42e6-90ec-f6a4b94ad495",
       "core": false,
-      "unlocked_by": "sum-of-multiples",
+      "unlocked_by": "series",
       "difficulty": 3,
-      "topics": ["arrays", "bitwise_operations"]
+      "topics": [
+        "arrays",
+        "bitwise_operations"
+      ]
     },
     {
       "slug": "bank-account",
@@ -367,7 +511,10 @@
       "core": false,
       "unlocked_by": "clock",
       "difficulty": 4,
-      "topics": ["classes", "concurrency"]
+      "topics": [
+        "classes",
+        "concurrency"
+      ]
     },
     {
       "slug": "acronym",
@@ -375,7 +522,10 @@
       "core": false,
       "unlocked_by": "two-fer",
       "difficulty": 4,
-      "topics": ["strings", "transforming"]
+      "topics": [
+        "strings",
+        "transforming"
+      ]
     },
     {
       "slug": "simple-linked-list",
@@ -383,7 +533,10 @@
       "core": false,
       "unlocked_by": "clock",
       "difficulty": 4,
-      "topics": ["classes", "lists"]
+      "topics": [
+        "classes",
+        "lists"
+      ]
     },
     {
       "slug": "matrix",
@@ -391,7 +544,10 @@
       "core": false,
       "unlocked_by": "kindergarten-garden",
       "difficulty": 4,
-      "topics": ["matrices", "parsing"]
+      "topics": [
+        "matrices",
+        "parsing"
+      ]
     },
     {
       "slug": "rotational-cipher",
@@ -399,15 +555,24 @@
       "core": false,
       "unlocked_by": "bob",
       "difficulty": 4,
-      "topics": ["algorithms", "strings", "transforming"]
+      "topics": [
+        "algorithms",
+        "strings",
+        "transforming"
+      ]
     },
     {
       "slug": "largest-series-product",
       "uuid": "4a6621bb-e55a-4ae2-89e3-3aa7e37a8656",
       "core": false,
-      "unlocked_by": "leap",
+      "unlocked_by": "series",
       "difficulty": 4,
-      "topics": ["integers", "math", "strings", "transforming"]
+      "topics": [
+        "integers",
+        "math",
+        "strings",
+        "transforming"
+      ]
     },
     {
       "slug": "house",
@@ -415,23 +580,22 @@
       "core": false,
       "unlocked_by": "raindrops",
       "difficulty": 4,
-      "topics": ["algorithms", "strings"]
+      "topics": [
+        "algorithms",
+        "strings"
+      ]
     },
     {
       "slug": "pythagorean-triplet",
       "uuid": "4d5a53df-3d6b-46cb-a964-71c676f3cd93",
       "core": false,
-      "unlocked_by": "leap",
-      "difficulty": 4,
-      "topics": ["integers", "math", "overloading"]
-    },
-    {
-      "slug": "series",
-      "uuid": "9ca46617-4995-45cc-a2dd-b8630eaa288b",
-      "core": false,
-      "unlocked_by": "sum-of-multiples",
+      "unlocked_by": "series",
       "difficulty": 4,
-      "topics": ["arrays", "strings", "transforming"]
+      "topics": [
+        "integers",
+        "math",
+        "overloading"
+      ]
     },
     {
       "slug": "twelve-days",
@@ -439,7 +603,10 @@
       "core": false,
       "unlocked_by": "bob",
       "difficulty": 4,
-      "topics": ["algorithms", "strings"]
+      "topics": [
+        "algorithms",
+        "strings"
+      ]
     },
     {
       "slug": "anagram",
@@ -447,7 +614,10 @@
       "core": false,
       "unlocked_by": "bob",
       "difficulty": 4,
-      "topics": ["filtering", "strings"]
+      "topics": [
+        "filtering",
+        "strings"
+      ]
     },
     {
       "slug": "word-count",
@@ -455,39 +625,56 @@
       "core": false,
       "unlocked_by": "bob",
       "difficulty": 4,
-      "topics": ["dictionaries", "strings", "transforming"]
+      "topics": [
+        "dictionaries",
+        "strings",
+        "transforming"
+      ]
     },
     {
       "slug": "prime-factors",
       "uuid": "456ffe2c-e241-4373-8bea-d4d328f815e9",
       "core": false,
-      "unlocked_by": "leap",
+      "unlocked_by": "series",
       "difficulty": 4,
-      "topics": ["integers", "math"]
+      "topics": [
+        "integers",
+        "math"
+      ]
     },
     {
       "slug": "meetup",
       "uuid": "064096c1-89b0-4656-bd3e-08ca833aa0b1",
       "core": false,
-      "unlocked_by": "accumulate",
+      "unlocked_by": "gigasecond",
       "difficulty": 4,
-      "topics": ["dates"]
+      "topics": [
+        "dates"
+      ]
     },
     {
       "slug": "all-your-base",
       "uuid": "de5e2eff-2b80-4996-a322-dc59ebe25edd",
       "core": false,
-      "unlocked_by": "accumulate",
+      "unlocked_by": "series",
       "difficulty": 4,
-      "topics": ["integers", "math", "transforming"]
+      "topics": [
+        "integers",
+        "math",
+        "transforming"
+      ]
     },
     {
       "slug": "pascals-triangle",
       "uuid": "d5d48857-5325-45d2-9969-95a0d7bba370",
       "core": false,
-      "unlocked_by": "accumulate",
+      "unlocked_by": "series",
       "difficulty": 4,
-      "topics": ["arrays", "control_flow_loops", "math"]
+      "topics": [
+        "arrays",
+        "control_flow_loops",
+        "math"
+      ]
     },
     {
       "slug": "isbn-verifier",
@@ -495,7 +682,12 @@
       "core": false,
       "unlocked_by": "bob",
       "difficulty": 4,
-      "topics": ["conditionals", "loops", "pattern_matching", "strings"]
+      "topics": [
+        "conditionals",
+        "loops",
+        "pattern_matching",
+        "strings"
+      ]
     },
     {
       "slug": "list-ops",
@@ -503,23 +695,33 @@
       "core": false,
       "unlocked_by": "grade-school",
       "difficulty": 5,
-      "topics": ["lists", "recursion"]
+      "topics": [
+        "lists",
+        "recursion"
+      ]
     },
     {
       "slug": "simple-cipher",
       "uuid": "54649fb0-6b14-44df-85af-ae1f7a62449d",
       "core": false,
-      "unlocked_by": "accumulate",
+      "unlocked_by": "series",
       "difficulty": 5,
-      "topics": ["algorithms", "strings", "transforming"]
+      "topics": [
+        "algorithms",
+        "strings",
+        "transforming"
+      ]
     },
     {
       "slug": "roman-numerals",
       "uuid": "d3702b93-7bb3-4e0a-8cd7-974ad93b0d3d",
       "core": false,
-      "unlocked_by": "accumulate",
+      "unlocked_by": "series",
       "difficulty": 5,
-      "topics": ["control_flow_loops", "transforming"]
+      "topics": [
+        "control_flow_loops",
+        "transforming"
+      ]
     },
     {
       "slug": "flatten-array",
@@ -527,7 +729,10 @@
       "core": false,
       "unlocked_by": "grade-school",
       "difficulty": 5,
-      "topics": ["lists", "recursion"]
+      "topics": [
+        "lists",
+        "recursion"
+      ]
     },
     {
       "slug": "binary-search-tree",
@@ -535,7 +740,11 @@
       "core": false,
       "unlocked_by": "grade-school",
       "difficulty": 5,
-      "topics": ["overloading", "searching", "trees"]
+      "topics": [
+        "overloading",
+        "searching",
+        "trees"
+      ]
     },
     {
       "slug": "minesweeper",
@@ -543,7 +752,10 @@
       "core": false,
       "unlocked_by": "kindergarten-garden",
       "difficulty": 5,
-      "topics": ["parsing", "transforming"]
+      "topics": [
+        "parsing",
+        "transforming"
+      ]
     },
     {
       "slug": "parallel-letter-frequency",
@@ -551,7 +763,11 @@
       "core": false,
       "unlocked_by": "nucleotide-count",
       "difficulty": 5,
-      "topics": ["dictionaries", "parallellism", "transforming"]
+      "topics": [
+        "dictionaries",
+        "parallellism",
+        "transforming"
+      ]
     },
     {
       "slug": "atbash-cipher",
@@ -559,7 +775,11 @@
       "core": false,
       "unlocked_by": "grade-school",
       "difficulty": 5,
-      "topics": ["algorithms", "strings", "transforming"]
+      "topics": [
+        "algorithms",
+        "strings",
+        "transforming"
+      ]
     },
     {
       "slug": "food-chain",
@@ -567,7 +787,10 @@
       "core": false,
       "unlocked_by": "allergies",
       "difficulty": 5,
-      "topics": ["algorithms", "strings"]
+      "topics": [
+        "algorithms",
+        "strings"
+      ]
     },
     {
       "slug": "grep",
@@ -575,7 +798,11 @@
       "core": false,
       "unlocked_by": "markdown",
       "difficulty": 5,
-      "topics": ["files", "searching", "strings"]
+      "topics": [
+        "files",
+        "searching",
+        "strings"
+      ]
     },
     {
       "slug": "sublist",
@@ -583,7 +810,9 @@
       "core": false,
       "unlocked_by": "grade-school",
       "difficulty": 5,
-      "topics": ["lists"]
+      "topics": [
+        "lists"
+      ]
     },
     {
       "slug": "tree-building",
@@ -591,7 +820,10 @@
       "core": false,
       "unlocked_by": "allergies",
       "difficulty": 5,
-      "topics": ["refactoring", "trees"]
+      "topics": [
+        "refactoring",
+        "trees"
+      ]
     },
     {
       "slug": "scale-generator",
@@ -599,7 +831,10 @@
       "core": false,
       "unlocked_by": "kindergarten-garden",
       "difficulty": 5,
-      "topics": ["algorithms", "parsing"]
+      "topics": [
+        "algorithms",
+        "parsing"
+      ]
     },
     {
       "slug": "bracket-push",
@@ -607,7 +842,10 @@
       "core": false,
       "unlocked_by": "bob",
       "difficulty": 5,
-      "topics": ["parsing", "strings"]
+      "topics": [
+        "parsing",
+        "strings"
+      ]
     },
     {
       "slug": "linked-list",
@@ -615,7 +853,10 @@
       "core": false,
       "unlocked_by": "clock",
       "difficulty": 5,
-      "topics": ["classes", "lists"]
+      "topics": [
+        "classes",
+        "lists"
+      ]
     },
     {
       "slug": "crypto-square",
@@ -623,7 +864,11 @@
       "core": false,
       "unlocked_by": "allergies",
       "difficulty": 5,
-      "topics": ["algorithms", "strings", "transforming"]
+      "topics": [
+        "algorithms",
+        "strings",
+        "transforming"
+      ]
     },
     {
       "slug": "ledger",
@@ -631,7 +876,11 @@
       "core": false,
       "unlocked_by": "allergies",
       "difficulty": 5,
-      "topics": ["globalization", "refactoring", "strings"]
+      "topics": [
+        "globalization",
+        "refactoring",
+        "strings"
+      ]
     },
     {
       "slug": "custom-set",
@@ -639,7 +888,9 @@
       "core": false,
       "unlocked_by": "book-store",
       "difficulty": 5,
-      "topics": ["sets"]
+      "topics": [
+        "sets"
+      ]
     },
     {
       "slug": "dot-dsl",
@@ -647,7 +898,11 @@
       "core": false,
       "unlocked_by": "clock",
       "difficulty": 5,
-      "topics": ["classes", "domain_specific_languages", "equality"]
+      "topics": [
+        "classes",
+        "domain_specific_languages",
+        "equality"
+      ]
     },
     {
       "slug": "ocr-numbers",
@@ -655,7 +910,10 @@
       "core": false,
       "unlocked_by": "kindergarten-garden",
       "difficulty": 5,
-      "topics": ["parsing", "pattern_recognition"]
+      "topics": [
+        "parsing",
+        "pattern_recognition"
+      ]
     },
     {
       "slug": "circular-buffer",
@@ -663,7 +921,10 @@
       "core": false,
       "unlocked_by": "markdown",
       "difficulty": 5,
-      "topics": ["classes", "queues"]
+      "topics": [
+        "classes",
+        "queues"
+      ]
     },
     {
       "slug": "luhn",
@@ -671,7 +932,11 @@
       "core": false,
       "unlocked_by": "markdown",
       "difficulty": 5,
-      "topics": ["algorithms", "strings", "transforming"]
+      "topics": [
+        "algorithms",
+        "strings",
+        "transforming"
+      ]
     },
     {
       "slug": "run-length-encoding",
@@ -679,7 +944,10 @@
       "core": false,
       "unlocked_by": "markdown",
       "difficulty": 5,
-      "topics": ["algorithms", "transforming"]
+      "topics": [
+        "algorithms",
+        "transforming"
+      ]
     },
     {
       "slug": "spiral-matrix",
@@ -687,7 +955,10 @@
       "core": false,
       "unlocked_by": "kindergarten-garden",
       "difficulty": 5,
-      "topics": ["algorithms", "matrices"]
+      "topics": [
+        "algorithms",
+        "matrices"
+      ]
     },
     {
       "slug": "yacht",
@@ -695,7 +966,11 @@
       "core": false,
       "unlocked_by": "bob",
       "difficulty": 5,
-      "topics": ["games", "parsing", "sorting"]
+      "topics": [
+        "games",
+        "parsing",
+        "sorting"
+      ]
     },
     {
       "slug": "tournament",
@@ -703,7 +978,10 @@
       "core": false,
       "unlocked_by": "kindergarten-garden",
       "difficulty": 6,
-      "topics": ["parsing", "strings"]
+      "topics": [
+        "parsing",
+        "strings"
+      ]
     },
     {
       "slug": "word-search",
@@ -711,7 +989,10 @@
       "core": false,
       "unlocked_by": "markdown",
       "difficulty": 6,
-      "topics": ["searching", "tuples"]
+      "topics": [
+        "searching",
+        "tuples"
+      ]
     },
     {
       "slug": "bowling",
@@ -719,7 +1000,10 @@
       "core": false,
       "unlocked_by": "markdown",
       "difficulty": 6,
-      "topics": ["algorithms", "control_flow_loops"]
+      "topics": [
+        "algorithms",
+        "control_flow_loops"
+      ]
     },
     {
       "slug": "transpose",
@@ -727,7 +1011,10 @@
       "core": false,
       "unlocked_by": "markdown",
       "difficulty": 6,
-      "topics": ["strings", "transforming"]
+      "topics": [
+        "strings",
+        "transforming"
+      ]
     },
     {
       "slug": "nth-prime",
@@ -735,7 +1022,9 @@
       "core": false,
       "unlocked_by": "book-store",
       "difficulty": 6,
-      "topics": ["math"]
+      "topics": [
+        "math"
+      ]
     },
     {
       "slug": "pig-latin",
@@ -743,7 +1032,10 @@
       "core": false,
       "unlocked_by": "book-store",
       "difficulty": 6,
-      "topics": ["strings", "transforming"]
+      "topics": [
+        "strings",
+        "transforming"
+      ]
     },
     {
       "slug": "rail-fence-cipher",
@@ -751,7 +1043,11 @@
       "core": false,
       "unlocked_by": "book-store",
       "difficulty": 6,
-      "topics": ["algorithms", "strings", "transforming"]
+      "topics": [
+        "algorithms",
+        "strings",
+        "transforming"
+      ]
     },
     {
       "slug": "change",
@@ -759,7 +1055,10 @@
       "core": false,
       "unlocked_by": "binary-search",
       "difficulty": 6,
-      "topics": ["arrays", "integers"]
+      "topics": [
+        "arrays",
+        "integers"
+      ]
     },
     {
       "slug": "palindrome-products",
@@ -767,15 +1066,23 @@
       "core": false,
       "unlocked_by": "saddle-points",
       "difficulty": 6,
-      "topics": ["algorithms", "math", "strings", "tuples"]
+      "topics": [
+        "algorithms",
+        "math",
+        "strings",
+        "tuples"
+      ]
     },
     {
       "slug": "complex-numbers",
       "uuid": "0ed2de0f-70da-4f04-834e-01bfb0aa48d3",
       "core": false,
-      "unlocked_by": "leap",
+      "unlocked_by": "space-age",
       "difficulty": 6,
-      "topics": ["math", "tuples"]
+      "topics": [
+        "math",
+        "tuples"
+      ]
     },
     {
       "slug": "poker",
@@ -783,7 +1090,11 @@
       "core": false,
       "unlocked_by": "kindergarten-garden",
       "difficulty": 7,
-      "topics": ["games", "parsing", "sorting"]
+      "topics": [
+        "games",
+        "parsing",
+        "sorting"
+      ]
     },
     {
       "slug": "diffie-hellman",
@@ -791,7 +1102,12 @@
       "core": false,
       "unlocked_by": "book-store",
       "difficulty": 7,
-      "topics": ["algorithms", "integers", "math", "transforming"]
+      "topics": [
+        "algorithms",
+        "integers",
+        "math",
+        "transforming"
+      ]
     },
     {
       "slug": "dominoes",
@@ -799,7 +1115,10 @@
       "core": false,
       "unlocked_by": "binary-search",
       "difficulty": 7,
-      "topics": ["arrays", "tuples"]
+      "topics": [
+        "arrays",
+        "tuples"
+      ]
     },
     {
       "slug": "rectangles",
@@ -807,7 +1126,10 @@
       "core": false,
       "unlocked_by": "kindergarten-garden",
       "difficulty": 7,
-      "topics": ["parsing", "transforming"]
+      "topics": [
+        "parsing",
+        "transforming"
+      ]
     },
     {
       "slug": "wordy",
@@ -815,7 +1137,11 @@
       "core": false,
       "unlocked_by": "kindergarten-garden",
       "difficulty": 7,
-      "topics": ["parsing", "strings", "transforming"]
+      "topics": [
+        "parsing",
+        "strings",
+        "transforming"
+      ]
     },
     {
       "slug": "zebra-puzzle",
@@ -823,7 +1149,9 @@
       "core": false,
       "unlocked_by": "book-store",
       "difficulty": 8,
-      "topics": ["logic"]
+      "topics": [
+        "logic"
+      ]
     },
     {
       "slug": "hangman",
@@ -831,7 +1159,10 @@
       "core": false,
       "unlocked_by": "saddle-points",
       "difficulty": 8,
-      "topics": ["events", "reactive_programming"]
+      "topics": [
+        "events",
+        "reactive_programming"
+      ]
     },
     {
       "slug": "diamond",
@@ -839,7 +1170,10 @@
       "core": false,
       "unlocked_by": "saddle-points",
       "difficulty": 8,
-      "topics": ["algorithms", "strings"]
+      "topics": [
+        "algorithms",
+        "strings"
+      ]
     },
     {
       "slug": "two-bucket",
@@ -847,7 +1181,9 @@
       "core": false,
       "unlocked_by": "saddle-points",
       "difficulty": 8,
-      "topics": ["logic"]
+      "topics": [
+        "logic"
+      ]
     },
     {
       "slug": "connect",
@@ -855,7 +1191,10 @@
       "core": false,
       "unlocked_by": "kindergarten-garden",
       "difficulty": 8,
-      "topics": ["parsing", "transforming"]
+      "topics": [
+        "parsing",
+        "transforming"
+      ]
     },
     {
       "slug": "say",
@@ -863,7 +1202,10 @@
       "core": false,
       "unlocked_by": "kindergarten-garden",
       "difficulty": 8,
-      "topics": ["strings", "transforming"]
+      "topics": [
+        "strings",
+        "transforming"
+      ]
     },
     {
       "slug": "react",
@@ -871,7 +1213,11 @@
       "core": false,
       "unlocked_by": "saddle-points",
       "difficulty": 9,
-      "topics": ["classes", "events", "reactive_programming"]
+      "topics": [
+        "classes",
+        "events",
+        "reactive_programming"
+      ]
     },
     {
       "slug": "variable-length-quantity",
@@ -879,7 +1225,10 @@
       "core": false,
       "unlocked_by": "allergies",
       "difficulty": 9,
-      "topics": ["algorithms", "bitwise_operations"]
+      "topics": [
+        "algorithms",
+        "bitwise_operations"
+      ]
     },
     {
       "slug": "go-counting",
@@ -887,7 +1236,11 @@
       "core": false,
       "unlocked_by": "saddle-points",
       "difficulty": 9,
-      "topics": ["optional_values", "parsing", "tuples"]
+      "topics": [
+        "optional_values",
+        "parsing",
+        "tuples"
+      ]
     },
     {
       "slug": "sgf-parsing",
@@ -895,7 +1248,10 @@
       "core": false,
       "unlocked_by": "kindergarten-garden",
       "difficulty": 9,
-      "topics": ["parsing", "transforming"]
+      "topics": [
+        "parsing",
+        "transforming"
+      ]
     },
     {
       "slug": "zipper",
@@ -903,7 +1259,11 @@
       "core": false,
       "unlocked_by": "markdown",
       "difficulty": 10,
-      "topics": ["recursion", "searching", "trees"]
+      "topics": [
+        "recursion",
+        "searching",
+        "trees"
+      ]
     },
     {
       "slug": "alphametics",
@@ -911,7 +1271,10 @@
       "core": false,
       "unlocked_by": "nucleotide-count",
       "difficulty": 10,
-      "topics": ["dictionaries", "parsing"]
+      "topics": [
+        "dictionaries",
+        "parsing"
+      ]
     },
     {
       "slug": "forth",
@@ -919,7 +1282,10 @@
       "core": false,
       "unlocked_by": "markdown",
       "difficulty": 10,
-      "topics": ["parsing", "stacks"]
+      "topics": [
+        "parsing",
+        "stacks"
+      ]
     },
     {
       "slug": "pov",
@@ -927,7 +1293,11 @@
       "core": false,
       "unlocked_by": "markdown",
       "difficulty": 10,
-      "topics": ["graphs", "recursion", "searching"]
+      "topics": [
+        "graphs",
+        "recursion",
+        "searching"
+      ]
     },
     {
       "slug": "rest-api",
@@ -935,8 +1305,10 @@
       "core": false,
       "unlocked_by": "markdown",
       "difficulty": 6,
-      "topics": ["json", "parsing"],
-      "deprecated": false
+      "topics": [
+        "json",
+        "parsing"
+      ]
     },
     {
       "slug": "binary",
@@ -980,23 +1352,22 @@
       "core": false,
       "unlocked_by": "bob",
       "difficulty": 4,
-      "topics": ["cryptography", "math", "strings"]
+      "topics": [
+        "cryptography",
+        "math",
+        "strings"
+      ]
     },
     {
       "slug": "darts",
       "uuid": "cdde6c8c-0608-467d-a749-b53ec6168ecc",
       "core": false,
-      "unlocked_by": "leap",
+      "unlocked_by": "space-age",
       "difficulty": 2,
-      "topics": ["floating_point_numbers", "math"]
-    },
-    {
-      "slug": "high-scores",
-      "uuid": "f52d9be9-7044-4001-8678-dcae91a8d7f3",
-      "core": false,
-      "unlocked_by": "sum-of-multiples",
-      "difficulty": 1,
-      "topics": ["lists", "strings"]
+      "topics": [
+        "floating_point_numbers",
+        "math"
+      ]
     },
     {
       "slug": "dnd-character",
@@ -1004,7 +1375,9 @@
       "core": false,
       "unlocked_by": "clock",
       "difficulty": 3,
-      "topics": ["randomness"]
+      "topics": [
+        "randomness"
+      ]
     }
   ]
 }