I decided to add coins and shops. The shopkeeper is the Yello-Bellee King from the second game. He will be hiding somewhere in each level. If you collect some coins scattered somewhere throughout each level, You can spend them on items that can help you solve the puzzles of each room. He can also sometimes challenge you to a mini-game to win some coins. You can see it all when 12 Rooms of Doom 4 releases in 2022.