It started off as a normal film but got about half way and just had a plot twist that I'm still not quite sure could be thought up by any sane person. The ending was also rather strange and unexpected too. If it didn't have the funny lines and the crappy slapstick violence, I would have hated the film completely, and even though I enjoyed those parts, I still wouldn't go to see it again because it wasn't worth the money.
See it if you like silly films that make you speechless from stupidity and look like they were thought up on a pub crawl like the (original) one in the film, feel free! However, if you more enjoy big-budget films with lots of well done CGI and other special effects, don't waste your money and use it as a boredom buster when it comes out on TV...if you're desperate.