Continuity mistake: In the scene where Lindsay and the other girl counselors are stripping down to go into the lake, one of the girl counselors unhooks Lindsay's bathing suit top for her. In the next shot, her top is hooked back up again.
Continuity mistake: When Ben and Susie are talking to the kids about being in the talent show, if you look at the window behind them, it is raining, but a few seconds later when the scene changes to outside, it is a bright and sunny day. Also, I was an extra in the movie (I sit in front of Abby and Lindsey when they're making out in the talent show) and it rained the whole time while they filmed the movie.
Continuity mistake: At the beginning of the movie, when Beth is talking to Henry for the first time, she says, "Space: the final frontier," and Henry's hands can be seen in the shot. He's holding them high and out while playing with the handle of the shovel. In the very next shot, both of Henry's arms are down by his waist. (00:07:40)
Continuity mistake: Right after Gene knocks Susie over with the door, the shot changes to a group of kids sitting against a wall. Notice the kid in the blue tie-dyed shirt and glasses. When the shot changes back to Gene, the same kid can be seen sitting at the end of the table next to the kitchen door. (01:01:50)
Continuity mistake: When Victor is driving away from the campsite to meet Abby, the driver's side window is up. After he crashes into the tree the window is completely down, and it wasn't shattered in the crash because the second after the crash the window is still up. It's only when the shot changes that the window is down. (00:36:40)
Continuity mistake: When Coop goes to Katie's room to talk to her, she's standing in the doorway. If you look behind him (from Katie's point of view), you will see it is raining outside. But the next second, when the camera changes shots, it has magically stopped raining. The camera changes shots again (from Katie's point of view) and it shows that it is raining outside again.
Continuity mistake: Right before Beth drives into town, the nurse runs down the hill to stop the car. When the nurse runs down, she runs past all the camp counselors sitting on the lawn to reach Beth who is parked directly in front of them. After the nurse runs away, you see the counselors run towards Beth's car, but at this point Beth is parked in a totally different spot, to the right of where they are sitting. (00:29:55)
Continuity mistake: At the very end of the capture the flag game, Coop and McKinley can be seen chasing the guy holding the flag. If you look at the other people running there's a guy in a bright red shirt and between shots he keeps switching between being on the right side of McKinley and the left. (00:51:05)
Continuity mistake: In the scene where Lindsay and the other girl counselors are preparing to go swimming in the lake, Lindsay removes her shorts twice.