Surely this is no masterpiece. If you'll enjoy this movie really depends on whether you're trying to take it serious or not. I believe I wouldn't have enjoyed it if I watched it alone but it was tons of fun watching it with friends and pointing out plot-holes, people's tendency to drop their weapons or the director's inclination to stick the camera onto different weapons.
While this does not speak for the actual "quality" of the film, I can say it is definitely possible to enjoy this movie. Although to be honest it tends to drag at points and becomes a bit repetitive (they see one of the murderers, knock him unconscious, run away and hide, one person gets killed - repeat) but i guess the characters are meant to act stupid since otherwise the movie would be over after 10 minutes (that's actually the case for most slasher movies). I do not believe this was meant to be such a serious movie and thus it should probably not be judged as such: It's a gory and silly flick. Still, even in that category there's better movies. As I said, it can get boring at times, there's a few unnecessary twists (especially the last scene) and some bad editing.
Note: I watched the badly dubbed German version so i can't really say much about the acting.