Enter these cheats / codes at the title screen.

Effect	Code / Cheat
Allow two players to select the same character	Down R1 Up L1 Triangle Circle
Begin level with Power of Love (sword from 7-2)	Square, Square, Square, X, Circle, X, Triangle
Changes coin sprites into animal sprites	Up, Up, Down, Down, Up, Up, Up, Up
Enables Blood Mode	X, Circle, X, Square, X, Circle Circle
Unlock Zombie Mode	Down, Up, Right, Down, Up, Right, Down, Up, Right, Right, Right