Activate the following cheats by entering the corresponding sequences of buttons at the menu with the "Campaign", "Bonus", and "Options" selections. To play with unlockable characters, after entering the code select "Bonus Features" and then select "Generation 1":

CHEAT FUNCTION - CHEAT CODE
All Missions - DOWN, UP, LEFT, RIGHT, RIGHT, RIGHT, UP, DOWN.
Cybertron Missions - RIGHT, UP, UP, DOWN, RIGHT, LEFT, LEFT.
Infinite Ammo - UP, DOWN, LEFT, RIGHT, UP, UP, DOWN.
Infinite Health - LEFT, LEFT, UP, LEFT, RIGHT, DOWN, RIGHT.
No Traffic, Police, or Military - RIGHT, LEFT, RIGHT, LEFT, RIGHT, LEFT, RIGHT.
Play as Megatron generation 1 - DOWN, LEFT, LEFT, DOWN, RIGHT, RIGHT, UP.
Play as Jazz generation 1 - LEFT, UP, DOWN, DOWN, LEFT, UP, RIGHT
Play as Robo-Vision Optimus Prime generation 1 - DOWN, DOWN, UP, UP, RIGHT, RIGHT, RIGHT.
Play as Starscream generation 1 - RIGHT, DOWN, LEFT, LEFT, DOWN, UP, UP.
Play as Generation 1 Cartoon Megatron - DOWN, LEFT, LEFT, DOWN, RIGHT, RIGHT, UP
Play as Generation 1 Cartoon Optimus Prime - DOWN, RIGHT, LEFT, UP, DOWN, DOWN, LEFT