If you go to see this movie with expectations you formed while watching the extremely violent trailers, you will set yourself up for misery and disappointment. Sucker Punch, despite being directed by Zack Snyder (he of 300 and Watchmen fame) has much more in common with One Flew Over The Cuckoo's Nest than it does with Dead or Alive or any other fighting game; in fact, the trailers' combination of hyper-stylized Japanese sword fighting and fantasy opponents (dragons, German steampunk zombies from the Great War, orcs) should be a major clue that what is going on in these scenes has no connection whatsoever with reality.
Which is appropriate, because the movie is about a young girl committed to an insane asylum. Her vile stepfather bribes the chief orderly to ensure that the girl will be given a lobotomy, and our heroine's desperate attempt to escape before having her brains stirred with a spoon is what drives all the action in the movie. You'd better pay attention, though, because there's some subtle stuff going on here, and if you're just munching your popcorn while waiting for the scantily clad heroines to waste a ton of bad guys, you're going to miss it. Also, Snyder has managed to carry off the difficult task of dressing up attractive young women in flattering costumes while placing them in a context that makes the combination not even remotely sexy. This is a feature, not a bug.
Should you go see it? Maybe. If you don't like movies that don't have entirely happy endings, this isn't for you. If you want mindless violent entertainment, this movie is also not for you. Me, I knew what I was going to get before I went in, and I think I got my my ten bucks' worth of entertainment. YMMV.