Batman Forever

Press start while in training mode

Enter the level select code and start a level. Whenever you want press Start+L+R to destroy everyone on the screen.

At the Title Screen, press Left, Up, Left, Left, A, B, Y

On the screen where you can change from "Training Mode" to "Normal Mode," press Left, Up, Left, Left, A, B, Y. Change the game type to "Normal," set the difficulty level and press Start. Then choose your character like you normally would and press Start to access the Stage Select screen. Finally, press Up, Down, Left and Right on the Control Pad to choose the stage you want and press Start again to begin the game.