Better than I expected!
The graphics are awesome. The raindrops on Nite Owl's suit, the dirty alleyways, and Rorschachs shifting mask all look great. Its no button mashing either. The combat is fun too.
One of my gripes though is that it can get quite repetitive, the level sub-areas seem copy-pasted sometimes and there are only like 5 types of goons at any given level.
There are loads of combos which all look quite painful (Teeth even fly out). Nite Owl fights better one on one with some wierd wrestling moves (I'll let that pass), and Rorschach fights groups with some AOE attacks, he's also able to pick up weapons like crowbars or bottles.
Its a little on the short side though. Guess thats what you get for that kind of price...
I'd say it is worth it if you've got 17 bucks to spare and are a fan of the book or the movie.