*SPOILERS* Liked the movie, but the ending...
...I thought the ending was a cop out. I was half expecting a twist as to who the killer was. There WAS a twist, but IMHO it was incredibly lame.
If I had re-written the movie, the killer would have been either the janitor or more likely the coach guy.
And the other thing I didnt like was the killing of the janitor, the only likeable guy in the movie. Having him go first almost ruined any sympathy for marty.
No doubt about this movie though, it had some awesome and original deaths in it. I may never go near a riding lawn mower again!