I had actually already written off this film in my head. Even more so after seeing plenty of negative revieuws for it.
Boy, was I wrong... Granted, the first couple of appearances of the piranhas made me think: "is that the best they could do with modern technology and a (I assume) reasonable budget?"
But they royally make up for that afterwards. The special effects during the scenes of the piranhas attacking the springbreak party are great!
It's not very scary and it's also not extremely gory (compared to some more recent gore flicks), BUT it's a very fun movie to watch. Bloodthirsty fish, gorgeous girls in (and out of) bikinis, sunshine, one-liners galore and characters you can empathize with. It's the most fun I've had watching a film so far in 2011.