Transformers: Autobots and Decepticons are essentially one game split into two “campaigns” in a shameless grab for fans’ wallets. All of the fundamental game mechanics, including controls, combat, and mission structure, are exactly the same, and even the first few levels are near-mirrors of each other. Both games are decent, though, and have a decidedly different tone, which means there are some who will benefit from purchasing both, while most will be best off picking one.
The games are in some respects Grand Theft Auto clones, except that instead of jacking vehicles you scan them to acquire their forms. Once you acquire multiple forms, choosing amongst them isn’t particularly convenient – you have to pause and go into another menu. However, that menu is surprisingly useful, outlining the stats of each form, including top speed, handling, acceleration, and energy. If you are a collection junky, you’ll get a kick out of just how many forms you can obtain. A nice touch is that your robot form changes to match the coloration and general shape of each vehicle.
Also ripped straight from GTA is the threat level - destroying human property gets the police on you, and there are varying degrees of pursuit just like in GTA – except instead of stars you accumulate autobot or decepticon icons. Transforming into a vehicle helps you hide and reduce the pursuit level. It is important to note that within this dynamic is where the two games differ. In Autobots, you of course are there to protect humans, so you usually avoid rampant destruction, and sometimes must protect humans from the decepticons. With Decepticons you are encouraged to attack humans, and are even required to increase your threat level to either lure autobots from hiding or to create distractions.