This patch causes rivals to be unlocked by default in multiplayer mode instead of requiring a two-controller cheat code to be entered in every time the game is started.
Panel de Pon (Japan):
File/ROM SHA-1: EAD855D774C9943F7FFB5B4F429B2DD07FB6F606
File/ROM CRC32: 14D70786
Tetris Attack (USA):
File/ROM SHA-1: 2DC56EAB3E70C0910AE47119D8B69F494E6000DF
File/ROM CRC32: 6C128210