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
During the mission as Ironhide when you help Jazz at housing estate south, you'll confront a Decepticon with a hose. You cannot damage 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.
Go to "The Suburbs" or "More Than Meets the Eye" levels. Go to the power plant to find a Decepticon there, but you can also bring one there. There will be 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 to cause a lot of damage. This can cause police cars to come at you if you are near the city. 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.
Megatron starts the fight in his jet form and shoots up to two rounds down at you. Use your shield to avoid them. After two rounds of firing, he will land and start 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 immediately 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 until he returns 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. Toss another car at him. If done successfully, he will attack you again. Use melee attacks on him. Once again, after a couple 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 cautious as 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 time after each attack. After that, you will fight him for the last time. Use melee to defeat him.
ACHIEVEMENT - HOW TO UNLOCK Pride of Bumblebee (60 points) - Collect all secret icons. Pride of Megatron (20 points) - Destroy 200 Autobot Drones. Pride of Optimus Prime (20 points) - Destroy 200 Decepticon Drones. Transform and Roll Out (10 points) - Transform once. Robots in Disguise (25 points) - Transform 500 times. Keeper of the AllSpark (75 points) - Achieve 100% completion. Sideways Motion (15 points) - Achieve full Slide Skill. Wrong Way! (15 points) - Ram 250 Cars Shot Putter (15 points) - Achieve full Throw Skill. Speed Demon (15 points) - Achieve full Speed Skill. What Challenge? (10 points) - Complete your first Challenge sub-mission. Pride of Ironhide (15 points) - Achieve full Heroic Skill. Pride of Brawl (15 points) - Achieve full Destruction Skill. Mad Skillz (40 points) - Achieve all Skill items on all levels We Don't Need Roads (15 points) - Achieve full Jump Skill. Root of all Evil (15 points) - Achieve full Evil Skill. Suburban Hero (25 points) - Bumblebee protects Sam in The Suburbs. Suburban Hero Challenger (20 points) - Complet all challenge sub-missions in The Suburbs. Neighborhood Watch (25 points) - Continue your defense of The Suburbs as Jazz and Optimus Prime. Neighborhood Watch Challenger (20 points) - Complete all challenge sub-missions in the suburbs. Could You Describe the Ruckus? (25 points) - Bumblebee causes a disturbance in order to escape the Hoover Dam with the AllSpark. The Ruckus? Challenger (20 points) - Complete all challenge sub-missions in Inside Hoover Dam. Downtown Defender (25 points) - The Last Stand has been made. There's only one thing left to do. Downtown Defender Challenger (20 points) - Complete all challenge sub-missions in Autobot City. Look to the Stars (50 points) - Megatron and the Decepticons are finished. Sand Blaster (25 points) - Qatar is destroyed. Sand Blaster Challenger (20 points) - Complete all challenge sub-missions in Qatar Desert. Suburban Scourge (25 points) - The Autobots fall before you. The Suburbs are done for. Suburban Scourge Challenger (20 points) - Completed all challenge sub-missions in The Hunt for Sam Witwicky. Air Traffic Destroyer (25 points) - Starscream's power knows no bounds. The airbase's defenses are obsolete. Air Traffic Destroyer Challenger (20 points) - Complete all challenge sub-missions in the Airbase. Downtown Demolisher (25 points) - The city is in ruins. There's only one thing left to do. Downtown Demolisher Challenger (20 points) - Complete all challenge sub-missions in the Decepticon City. Finish this Planet (50 points) - Optimus and the Autobots are but a memory. Earth is yours. Weapon Systems Inactive (20 points) - Complete Suburbs Chapter 1 using only melee attacks. Sharp Shooter (40 points) - Complete Airbase Chapter 3 with more than 2:30 minutes remaining. Turbo? We don't need no turbo! (30 points) - Complete Hoover Internal Chapter 2 without using boost. Land Shark (10 points) - Spend 2 minutes underground. Batter Up (10 points) - Find a bat and make your enemy fly. Pit Crew (10 points) - Use a large tire to harm your enemy. Ring-A-Ding-Ding (10 points) - Use the Helio phone as a weapon. I Know Kung-Fu (30 points) - Perform 1,000 punches.