Transformers DS review at Gamespot.

"Transformers: Autobots and Transformers: Decepticons are two sides of the same coin. Both games tell the same general story, they both share the same environments, and they both let you run amok as a robot that can transform into various vehicles. The main thing distinguishing the two versions is that you fight as a heroic Autobot in one and an evil Decepticon in the other. Regardless of which version you choose to bring home, you'll probably get a kick out of beating up opposing robots and exploring the huge 3D environments incognito as a car, helicopter, or some other Earthly conveyance. The bad news is that the uninspiring story missions and brief overall length pretty much guarantee you'll be done with the game for good in six hours or less."

Full Source: Gamespot