Enjoying it so far. It's set very early in the war and the Decepticon campaign is first. For the first chapter, Megatron leads an assault on an orbital science facility commanded by some fellow named Starscream by crashing a starship into it. He's chasing something called Dark Energon (the story isn't taking itself too seriously). Once Starscream sees Megatron can control it he switches sides (Jetfire is not impressed) and you head back down to Cybertron to reactivate an energon bridge. The third chapter is a full scale assault on the Autobot city-state Iacon. I haven't started that yet, but it strikes me as an ideal time for the really big Transformers to start appearing, as promised in the spectacular intro movie.
I had the choice of actually playing Megatron in the first chapter, but I wasn't sure what the game would expect of me if I took command of the squad. Nothing much really, it turns out, which is why I played as Starscream in the second chapter. The characters tend to argue amongst themselves while you're running around. Not so noticeable in the first chapter - I mean who gives Megatron attitude? - but Starscream and his Sweepers insult each other quite a bit. I have also found myself starting to switch back and forth between robot and vehicle modes a lot more as I get comfortable with the control system. This is the first non-MMO I've played in something like six or seven years, and even then I mostly played WoW, so I've had some muscle memory to overcome.
Also, being able to transform into a jet is really handy for when you accidentally jump off into space, or over a really, really long drop. A tank, not so much.
I think the Autobot leader at the moment is Zeta Prime, who we are likely to kill off at the end of the Decepticon campaign I suspect, setting the stage for the Autobot campaign and the ascension of an Autobot officer named Optimus Prime...