Cheat mode:
Pause game play, then enter the "Fortress of Solitude" options menu. Enter one of the following codes at this menu to activate the corresponding cheat function.
God mode:
Press Up, Up, Down, Down, Left, Right, Left, Right, Y, X.

All power-ups:
Press Left, Y, Right, X, Down, Y, Up, Down, X, Y, X.

All unlockables:
Press Left, Up, Right, Down, Y, X, Y, Up, Right, X.

Unlimited city health:
Press Y, Right, Y, Right, Up, Left, Right, Y.