Puyo Pop Fever
Use all characters in Endless mode:
Press Up, Down, Triangle, Square, Start at the Endless screen.
Use all characters in Single mode:
Press Down, Up, Square, Triangle, Start at the Single screen.
In Options > Gallery, highlight 'View Cutscenes'. Hold the Square button and push Up, Down, Left, Right.
Thanks to Revolution reader krimbull504, Ashura, piggypete!