Press Start to pause game play in arcade mode, then press Circle, X, Right, Left, Right, Left, Down, Down, Up, Up. Five seconds from the timer will be converted to one half of a life. This code can be repeated.

Press Start to pause game play in arcade mode, then press Up, Up, Down, Down, Left, Right, Left, Right, X, Circle. One half of a life will be converted into five extra seconds. This code can be repeated.

Intentionally lose the game by dying repeatedly to increase the number of lives per credit between four to six.

Intentionally lose the game by allowing the timer to run out repeatedly to increase the time limit between seventy and eighty.

After continuing the game 16 times, you will be able to increase the credits to three on the options screen.

After you defeat the big Boss by shooting him three times, he will hang from the tower. Shoot the chain and complete the game that way to unlock time attack boss mode.

After continuing the game 31 times, you will be able to increase the credits to four on the options screen.

After continuing the game 101 times, you will be able to increase the credits to infinite on the options screen.

After you defeat the big Boss by shooting him three times, he will hang from the tower. If you shoot him or the girl, they will both fall. You will complete the game and unlock survival boss mode.