This movie was pure insanity. It’s two and a half unrelenting hours of explosions, robots and boobs. I would say it’s equally divided between moments of sheer brilliance, and WTF moments. If you’ve seen the first movie, then you have a good idea of what to expect, but crank it up a notch. This movie makes everything more extreme, both the good and the bad. When I walked out, at first, I wasn’t sure if I really liked it. Overall, I’ve decided I enjoyed it, but wow. Talk about over-the-top.

For another perspective, here’s an excerpt from a review on io9:

Michael Bay understands that summer movies are about two things: male anxiety, and pure id. That’s why he casts Shia LaBoeuf, that supreme avatar of pure male inadequacy, in the lead role. …LaBoeuf, who’s actually a fine actor, is the stand-in for the male viewers’ greatest fears about themselves. No matter how great a loser they might be, they can’t be as losery a loser as Sam Witwicky. And yet, Sam has awesome giant robots stomping around telling him he’s the most important awesome person ever. And he has the hottest girlfriend in the universe, Megan Fox, for whom banality is a huge aphrodisiac.
– io9, “Micheal Bay Finally Made an Art Movie“