Okay, so... you all know that I have a weakness for bad horror movies, right? I mean, even the really awful ones? Well, guess what genre Cabin Fever II: Spring Fever falls into?
I'd warn you that there are spoilers ahead, but let's face it: for a movie like this, nobody is going to care.
Let's start by considering the fact that the name makes very little sense in terms of the plot. (The disease doesn't actually cause any sort of fever, and the cabin from the original film is completely absent from the sequel.) Follow that with the observation that the horror-related portions of the plot made very little sense. (Who are the guys in vans? Why are they locking everyone in the school, and then killing them? If they're trying to suppress the outbreak of the disease, wouldn't a quick bit of arson be simpler - and, by the way, how did they know about the outbreak anyhow?)
This would be even more of a problem if the horror elements were more prominent; as it stands, the plot is more of a John Hughes teen-angst drama. Consider, for example, where it places the dramatic tension: in the high school relationships. Will the protagonist end up with the girl of his dreams? Will she get rid of her abusive boyfriend? Will their friend find a date for the prom? So, yeah: it's a teen rom-com which just happens to end with everybody dying horribly from a flesh-eating disease. Which, you know, if that's your thing, then great; I was hoping for more of a horror film, myself.
To be fair, the acting is actually pretty good; I can't fault the actors, except possibly for not finding a better production in which to showcase their skills.
The movie did, however, offer one completely new experience for me. By the time we got to the prom, I really wanted to insert myself into the movie (a la Pleasantville). The reason for this was simple: I was so completely annoyed by every single character in the film that I seriously wanted to go in there and kill them all myself, before they had a chance to die from the disease. Which, from a plotting-and-characterization perspective, is kind of a problem.
Listen, if you're going to make horror films, there's really only one rule. Be scary. Because let me tell you, the alternate ending of the film? The one in my head, featuring me as a spontaneous mass-murderer? Yeah, lame as that was, it would still have been a lot more scary than what was actually on the screen.