I think part of the reason this movie was made...and is aimed at us gamers who actually play all the Nancy Drew PC games. There's been a lot of movies lately based on video games, and I think this in one of them.
So this movie does not follow any book. But it does follow parts of the games. I buy and play every Nancy Drew games as soon as it comes out. And the games are from HerInteractive and are for "girls who aren't afraid of a mouse!" And some of these games actually won Parents' Choice Gold Awards. They are not only fun but you can actually learn a thing or two while playing.
I took two of my step children with me to go see it and they loved it! The 10 yr. old had started playing her first Nancy Drew game a day before I took her to see the movie, and she was having so much fun playing the game I thought she would enjoy the movie as well. And I was right...she not only loved this movie but couldn't wait to get home to finish her first game and start another one.
My other step daughter is only 7 and she also loved the movie but she is still a little to young too play the games yet, but she enjoys watching her sister play at times just to see what's going on.
The games are based for children 10 yrs and older. All the games usually get pretty descent reviews and are classified as adventure games. For more information on the games just check out HerInterative Nancy Drew games. So personally I thought the movie was pretty good and I will buy it when it comes out on DVD.

I've rented and watched this movie for the 1st time on DVD without reading any reviews about it. So, after 15 minutes of watching I've noticed that something is wrong with this movie; it's TERRIBLE! I mean, in the trailers it looked scary and serious!
I think that Eli Roth (Mr. Director) thought that if all the characters in this film were stupid, the movie would be funny...(So stupid, it's funny...? WRONG!) He should watch and learn from better horror-comedies such as:"Fright Night", "The Lost Boys" and "The Return Of the Living Dead"! Those are funny!
"Cabin Fever" is THE reason why I registered to www.IMDb.com so I can release my thoughts of discontent about it.
I've decided to watch the movie a second time >AAARGH!< and make notes for my partial "review" to show how foolish the movie is. "Resident Evil" (horror) or "Dude, Where's My Car?" (comedy) I can watch over and over again and still enjoy! But this...!
How bad can a script and a director be??? This bad. Here are the awful scenes in chronological order:
In the early scenes we see Henry, who doesn't realize his dog lying on the ground with its tongue hanging out of its mouth and dead-glazed stare is dead!
The movie doesn't explain anything about the blonde long-haired kid who like to bite people.
And my answer to Marcy's unanswered question ("What's wrong with the woods?") is "nothing". The script has that bearded guy warn them about the woods just for "suspense".
Then the "smartest" of the 5-pack, Bert, almost gives us an example of how to start a forest fire. He meets now-infected Henry who begs for help and from here on the movie wants to break the record in using the "F-word". Bert starts to freak out because Henry looks awfully ill. Bert:"Don't make me shoot you!" (he forgets to add: "...with my BB gun!")
Bert heads back to the cabin but how about that? He meets Marcy and Jeff who were having sex, but now suddenly decide to go out for a walk! Marcy wisely takes out the unguarded campfire Bert had started earlier (A moment of clarity for a change?) Bert doesn't mention a word about Henry because the fool thinks he has killed him with his BB gun.
Later, as the Five Estupidos sit around their campfire, another weirdo shows up with his dog. (Maybe that's what the warning about the woods is all about? It's filled with weirdos...and their dogs!?) They let him sit with them only because he has a huge bag filled with cannabis. (Their brains are completely intoxicated! No wonder why they are all so DUMB!) This is the last time we'll see this forgettable character...alive!
Henry shows up at their cabin, (NOTE: He was lying all the time a few yards from their cabin!!!) looking worse, almost like a zombie, covered in goo! He says he needs a doctor. But the Young Einsteins refuse to help the poor sucker. He gets into their unlocked truck which of course also has its key in the ignition. Henry almost seems smart enough to drive the Hell away from there but instead starts puking blood all over the dashboard, seats and windows. The Fantastic Five come out running, armed with: a BB Gun, a knife, a baseball bat (*huh? Ever tried playing baseball in the middle of the woods???), a poker, and a (insecticide?) spray-can, ready to combat the single, unarmed and terribly sick man. (clever script!) Bert manages to kill the car with one single shot of his BB Gun, which is only possible in the mind of director Eli Roth. "What else am I supposed to do?" Bert yells in his defense. Jeff and Paul try to knock Henry down with their bat and poker but miss and crash the truck's windows instead. Henry walks up to the dumb girls who say: "He's coming towards us!" (Thanks for the info, dumb broads, I can see that! But I don't think he wants to do you any harm!) Marcy sprays in his eyes, making Henry yelp! And our "hero" Paul touches Henry's arm with a burning log from the campfire, which they recklessly left burning while they were INSIDE the cabin! (Where has all that wisdom gone? I guess the cannabis had started to take its toll!:-) Henry turns into The Human Torch and runs away, screaming.
The following day, Bert and Jeff head out for a mechanic. And Marcy decides to "go for help" all by herself, in the woods, as Paul stays behind with Karen...Doesn't that sound idiotic? Marcy could have stayed with Karen and Paul because Jeff and Bert were already "going for help"!
I skip my comments now to how we suddenly see Marcy in a CANOE rowing over a huge and winding river! How did she get a canoe? Does she even know where she's going!? Anyway, she goes to the riverbank and finds a very big and seemingly abandoned cabin and, like in most horror movies, walks inside the cabin saying:"Hello? Is anyone there?" Bert suddenly pops up from behind a furniture and scares her (and me at first). And along comes Jeff, as well. How did THEY get here!? Did they swim across the river??? Do you see how brainless the script is!?
Deputy Winston meets Paul at the cabin. He somehow doesn't notice the blood on their truck. This happens around 35 minutes of viewing and I have decided to stop torturing myself anymore and popped the DVD out. (Before I take my own eyes out!...Now, THAT's funny!)
If you liked this movie, do yourself a favor and watch "Fright Night", "The Lost Boys", or "The Return of The Living Dead". Then you'll see they are MORE entertaining than this...thing. Even the "Toxic Avenger part 2", which is also a lousy film, is way MORE funnier than "Cabin Fever".