Simple hack that disables the level up mechanic, the level selected at the beginning of the game will be kept through all the game. Now you can have a pleasant level 0 playthrough to kick back and enjoy yourself, perfect for those nights when you just can't manage to sleep.
Database match: Tetris (World) (Rev 1)
Database: No-Intro: Game Boy/Color (v. 20210227-015730)
File/ROM SHA-1: 74591CC9501AF93873F9A5D3EB12DA12C0723BBC
File/ROM CRC32: 46DF91AD