This is a pure meta: answers are all we need to solve this puzzle. Each answer from the Matropolis round consists of two words. One of the words can have a letter replaced to form a different word that follows the word PLAY in an English word or phrase. This is strongly clued by the title. The other word has a unique length between 3 and 10, which we can use to sort the answers. Reading the replacing letter spells out the answer ACT IT OUT.
|Puzzle Title||Answer||Play Word or Phrase||Extra Word (length)||Replacing letter|
|Puzzle Not Found||DIY TEA||Playday||TEA (3)||A|
|Solve, Index, Sort, Identify||PINE BARK||Playback||PINE (4)||C|
|Alchemystery! WALKTHROUGH version 0.01||FRESH LIME||Playtime||FRESH (5)||T|
|Mouth Mash||DOUBLE TRACKS||Play tricks||DOUBLE (6)||I|
|Functional Analysis||LISP MACHINE||Playlist||MACHINE (7)||T|
|This Anagram Does Not Exist||BASTILLE DAWN||Play down||BASTILLE (8)||O|
|⭐ Battle Star ⭐||HORSE LATITUDES||Playhouse||LATITUDES (9)||U|
|Union of Intersections||PHILIPPINE SEA||Playset||PHILIPPINE (10)||T|
PX: This metapuzzle went through several iterations and titles. The most recent one changed the title from "Play With Me", which almost made it into this hunt. We nerfed the metapuzzle at the last minute because we feared based on testsolvers that this would be the last meta every team would solve. We also made a last-minute change that replaced the answer of DANGEROUS HORSE with HORSE LATITUDES to veer away from the idea that the first word always contributes to the length when sorting.
Initially we tried to stick with just toys, here's a very early draft's set of answers (feel free to try to solve it yourself - you may have tried some of these ideas when solving this puzzle!):
Tots "R" Us : CARBON CLICKERS, CINNAMON ROLLS, CORN DOGS, HUMAN CONDITION, NYMPHADORA TONKS, PINKY AND THE BRAIN, STINKY SQUID, YOLO SWAG 420
There were some clear issues with this proof-of-concept (constrained answers, numbers, and multiple words in the other "half"). We also did not find many unambiguous one-word toys, and other toys or brands are too far from real words.
Taking inspiration from the old answer phrase, we pivoted to words relating to PLAY, initially allowing both words that come before or after. We were able to tighten some of these constraints, and we constructed this following set of answers, much closer to our current idea This set had a couple of its own issues, e.g. BAY could go to both BOY and DAY; Play Store is a brand, some of these answers were hard to fit in puzzles, etc
|Puzzle Title||Answer||Play...||Replacing letter|
|A Zoomer Thing||MUTE ALL||MATE||A|
|Problem Set #3||COIN BANK||BACK||C|
|Global Warming||SEA LEVEL||SET||T|
|Prehistoric Memes||LAST SUPPER||LIST||I|
|Problem Set #4||PERFECT SCORE||STORE||T|
|Every Party Needs a Healer||TREANT PROTECTOR||TRUANT||U|
|Cinco de Mayo||LIME MARGARITAS||TIME||T|
Finding words that fit the meta constraints while still yielding interesting or thematic answers (and preventing heavy backsolvability) was difficult, and so a lot of the answers we ended up with in this puzzle were fairly random "phrases".