To unlock the following, insert the passwords on the main menu (where campaigns can be selected, et cetera)…G1 Jazz Skin - Left, Up, Down, Down, Left, Up, Right
G1 Megatron Skin - Down, Left, Left, Down, Right, Right, Up
G1 Optimus Prime Skin - Down, Right, Left, Up, Down, Down, Left
G1 Starscream Skin - Right, Down, Left, Left, Down, Up, Up
No Vehicles, Military, or Police - Right, Left, Right, Left, Right, Left, Right
Robovision Optimus Prime Skin - Down, Down, Up, Up, Right, Right, Right
Unlock All Missions - Down, Up, Left, Right, Right, Right, Up, Down
Unlock both Cybertron Missions - Right, Up, Up, Down, Right, Left, Left
Unlock Unlimited Ammo - Up, Down, Left, Right, Up, Up, Down
Unlock Unlimited Health (Invincibility) - Left, Left, Up, Left, Right, Down
Unlockable: Character Skins
To unlock the following skins, fulfill the corresponding condition in the game…G1 Jazz - Complete all sub-missions (both campaigns)
G1 Megatron - Acquire all Decepticon icons
G1 Optimus Prime - Acquire all Autobot icons
G1 Starscream - Finish the Decepticon campaign
Robovision Optimus Prime - Finish the Autobot campaign