Hold L + R and press Up, Down, Right, Left, X, B, Y, A at the title screen to unlock all hidden characters and rulesets.
Puyo Sniper
First, beat all of the stories with a S rank. Then go to the options menu and Puyo sniper will be selectable.
Puyo variations
Complete the indicated task to unlock the corresponding variation.
Bean (8 player): Get two "S" ranks in Story mode.
Block (8 player): Get 8 "S" ranks in Story mode.
Box (8 player and 2 to 4 player): Get a high score on Endless Fever.
Capsule (8 player and 2 to 4 player): Get a high score on Endless Battle Fever.
Charcoal (2 to 4 player): Get 22 "S" ranks in Story mode.
Human (8 player and 2 to 4 player): Get a high score on Endless Battle 2.
Morolian (2 to 4 player): Get 16 "S" ranks in Story mode.
MSX (2 to 4 player): Get 12 "S" ranks in Story mode.
Sonic (2 to 4 player): Get 22 "S" ranks in Story mode.
Star (8 player): Get 4 "S" ranks in Story mode.
Tile (8 player): Get 6 "S" ranks in Story mode.