Transformers: The Game

Unlimited health:
Press Left(2), Up, Left, Right, Down, Right at the menu with the "Campaign", "Bonus", and "Options" selections. The screen will flash to confirm correct code entry.

Ammo no reloaded:
Press Up, Down, Left, Right, Up(2), Down at the menu with the "Campaign", "Bonus", and "Options" selections. The screen will flash to confirm correct code entry.

All missions:
Press Down, Up, Left, Right(3), Up, Down at the menu with the "Campaign", "Bonus", and "Options" selections. The screen will flash to confirm correct code entry. All missions including the two special missions will be unlocked.

Bonus Cybertron missions:
Press Right, Up(2), Down, Right, Left(2) at the menu with the "Campaign", "Bonus", and "Options" selections and start through replay missions. The screen will flash to confirm correct code entry.
Reuben R..

No traffic, police, or military:
Press Right, Left, Right, Left, Right, Left, Right at the menu with the "Campaign", "Bonus", and "Options" selections. The screen will flash to confirm correct code entry. The only vehicles remaining will be parked.

Play as Optimus Prime Generation 1 version:
Press Down, Right, Left, Up, Down(2), Left at the menu with the "Campaign", "Bonus", and "Options" selections. The screen will flash to confirm correct code entry. Select the "Bonus Features" option then the "Generation 1" option to use the new appearance.

Alternately, collect all the Autobot Faction Symbols in the Autobot story line.

Play as Robovision Optimus Prime:
Press Down(2), Up(2), Right(3) at the "New Game" main menu. The screen will flash red to confirm correct code entry. Go the "Bonus Features" option then the "Generation 1" option to select "Robovision Optimus"
Ya Face!.

Alternately, successfully complete the Autobot story line.

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. Select the "Bonus Features" option then the "Generation 1" option to use the new appearance.
pyhv p, yhoeo.

Alternately successfully complete the Decepticon story line.
zerosk8r.

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

Play as Megatron Generation 1 version:
Press Down, Left(2), Down, Right(2), Up at the menu with the "Campaign", "Bonus", and "Options" selections. The screen will flash to confirm correct code entry. Select the "Bonus Features" option then the "Generation 1" option to use the new appearance.

Alternately, collect all the Transformer Shields in the Decepticon story line.

Hint: Defeating the cement truck Decepticon:
When you are fighting the cement truck Decepticon as Ironhide, to knock him down transform and run him over. Then, pick him up and throw him.
Ultispiderman120.

Hint: Defeating the Decepticon with a hose:
During the mission when you are Ironhide and help Jazz at housing estate south, there is a Decepticon with a hose. You cannot hit him with melee attacks until you throw something at him. After that, you can pick him up, or when he gets up you can use melee attacks.
Calum Heffernan.

Hint: Defeating Decepticons:
Go to "The Suburbs" or "More Than Meets the Eye" levels. Go to the power plant. There is already a Decepticon there, but you can also bring one there. You will see some capsules marked "Danger, High Voltage". There are about 100 of them at the power plant. Pick up a capsule and throw it at the Decepticon. The capsule is highly explosive and causes quite a lot of damage. Make sure you are not caught in the explosion or you will be sent flying through the level. Also if you are closer to the city, this sometimes causes one or two police cars to come at you. There are a few of these capsules also at the junkyard. The same can be done with gas trucks in the junk yard or the gas tanks in the gas station near the junk yard.
supacooldude3000.

Hint: Defeating Megatron:
Megatron is the final opponent in the Autobots storyline. He will first be in his jet form and shoot up to two rounds down at you. Avoid that by using your shield. After two rounds of firing, he will land. His next attack is ramming. You cannot hit him while he is still focused on ramming. When he stops ramming and stands up in one place looking around, pick up any car and quickly throw it at him. If not done fast enough, he will return to ramming. If that happens, wait for him to stop again. If done successfully, he will now attack you. Hit him in close range combat with your melee attacks. After a few hits, he will return to being a jet. Again after two rounds of firing he will return to the ground. In his second attack, he will use his ball and chain. Throw another car at him. If done successfully, he will attack you again. Use melee attacks on him. Once again after a few hits he will become a jet and fire at you. Do same as before to avoid that attack. After firing at you, he will go back to the ground. His third attack is the flamethrower. Be careful because it will be difficult to get cars to throw at him. When he is hit by a car you threw, he will attack again. Use melee attacks on him. For the last time he will become a jet again. Use the same strategy used earlier to avoid the attack. He will land after few hits and attack you with all the attacks he used previously. Throw cars at him every after each attack. After that, you will fight him for the last time. Use melee to defeat him.
Bill Dimalanta.

Glitch: Barricade hydraulics:
Choose the Decepticons and choose "The Hunt For Sam Witwicky" level. Go to the sports shop next to the mall. Then, go to the gas station and face the mall. There should be a jump. Transform and go off the jump into the building on the right. Note: Make the jump off the side of the ramp and use boost when you are close to the ramp. When Barricade hits the building, make sure that he lands upside down (do not transform when this happens). Wait a few seconds and Barricade will flip over. When he does he should be bouncing up and down with his wheels on the ground, sitting still. This may require a few attempts.