Infinite Health:
Press Left(2), Up, Left, Right, Down, Right

No Ammo Reload:
Press Up, Down, Left, Right, Up(2), Down

No Military or Police mode:
Press Right, Left, Right, Left, Right, Left, Right

Unlock All Missions and Extras:
Press Down, Up, Left, Right(3), Up, Down

Play as Optimus Prime Generation 1 version:
Press Up(2), Down(2), Right(3) at the "New Game" main menu. The screen will flash to confirm correct code entry.

Play as Starscream Generation 1 version:
Press Right, Down, Left(2), Down, Up(2) at the "New Game" main menu. The screen will flash to confirm correct code entry.

Play as Jazz Generation 1 version:
Press Left, Up(2), Down, Left, Up, Right at the "New Game" main menu. The screen will flash to confirm correct code entry.

Generation 1 Megatron:
Find all the Transformer Shields in the Decepticon story line.

Generation 1 Robo-vision Optimus Prime:
Complete the Autobot story line.

Generation 1 Optimus Prime (cartoon model):
Find all the Autobot Faction Symbols in the Autobot story line.