The game diverges from the anime and comic in terms of storyline. In the opening sequence Megatron, in a final assault against the Autobot Headquarters on Cybertron, surprises Optimus Prime with his Decepticlones, a massive powerful drone army. With numbers on his side, Megatron is able to overcome the resistance and fight Optimus Prime one-on-one. Megatron is about to kill Optimus Prime, and in an homage to the original movie, he says: "I would have waited an eternity for this. It's over, Prime". When a Mini-Con beacon activates on Earth, Megatron, well-aware of what this means, heads to Earth to claim the Mini-Cons. The Autobots Optimus Prime, Red Alert, and Hot Shot arrive on Earth as well to rescue the Mini-Cons, knowing that their combined power is the only way to overcome Megatron's new army.
Players control Optimus Prime, Red Alert or Hot Shot, who are able to transform between robot and vehicle modes at the push of the triangle button. The game revolves around the collection of Mini-cons, which can be equipped to the Transformer. These include weapons; such as a pistol, support items; such as glider wings, and stat-enhancement; such as an armour boost, and with the exception of the latter, can be controlled using the shoulder buttons. Only four or fewer can be equipped. The 'R1' primary weapon will always be assigned, and if none (Mini-con) are chosen, the default rifle is used in its stead. There is a limit to what Mini-cons can be equipped with respect to the power game mechanic, with more powerful Mini-cons taking up a lot of space. The more of the same colour/suit Mini-cons equipped, the stronger one's character will be. This is referred to as Mini-con linking. For the most part, the Mini-cons do not change the aesthetics of the transformer.
The worldwide debut of the Transformers PlayStation 2 demo occurred at TransformersCon on March 12–13, 2004. In September 2005, Atari released a Directors Cut of the game exclusively in the EU. This version includes several "Making of" movie clips and commercials on the game disc. A playable demo was included on the disc for Driv3r. Australian band Regurgitator provided the soundtrack to the game. The song "Wishbone" by the band Dropbox was used to promote the game.