We'll start with the driving. The vehicles often have squirrely handling, you can't switch from a robot to a car while in midair, and a tree sloth could climb buildings faster than you - handicaps that add up to tranquilize what could have been amazingly fluid and absolutely genre-destroying one-of-a-kind chase sequences.
Luckily, the Decepticon campaign has much less of a problem in this area. It's focus on mostly flying and even burrowing transformers - and the less claustrophobic environs they travel - makes navigation a much simpler affair. Also, for one reason or another, the vehicles seem less swoopy in this version, and when you're hot-rodding after an opponent with guns blazing, targeting them is simpler than in other console versions. It helps a lot.
But it still has other problems, which leads us to the blowing stuff up bit. Your target lock can't remember what "lock" means, but it almost doesn't matter. Why? Because, even though every single transformer has bullet-spraying space-artillery, every non-grunt enemy has a force field that renders him immune to gunfire, even in vehicle mode. You do have a basic, three or four-punch combo that you'll find yourself tediously hammering out ad nauseum, but it too will be ineffective 90% of the time because these bums block so constantly, they should transform into turtles instead of vehicles.
Luckily, thrown objects like cars, trees, and chain link fences can inexplicably tear right through an opponent's guard. So your skyscraper-perforating guns and metal-shearing punches may prove useless, but your enemy has no defense against the unstoppable power of an elm sapling you've pulled up and flicked in his direction. True, even heavy projectiles like cars rarely do more than nick your foe's health bar, but they can stun him and give you a chance to squeeze in a punch or two before he resumes his invulnerable cower behind crossed forearms again.
And again, the Wii version's controls win out here, being the only one that makes it easy to strafe, aim exactly where you want to, and heave whatever you're holding at the other guy's head. It's a critical improvement, given what an unexplainably critical tactic throwing stuff turns out to be. But overall, this is still far from the bombastic giant robot battles we were eagerly anticipating.