At the pause menu:
Alternate walking animation:
While playing, press pause then press L1, R1, L1, R1, L1, L1, R1, R1, Square.
While playing, press pause then press Up, Up, Down, Down, Left, Right, Left,
Right, Square, Triangle.
Start a new game and enter SPELUNKER as a name. This mode has alternate
dialogue, death with one hit, and the death sound from the original Spelunker.