These characters were all supposed to be teenagers, but several of them do not act or look like teenagers. Second, one of the characters has been sent to the island by her foster parents, and I'm pretty sure foster parents don't have the right in most states to send the child they are looking after away, to an island. Lastly, there are a few characters, including Enid and Dino, who weren't given the backstories to make the audience care about what happened to them, which was a shame since they seemed integral to the story.
This is not saying that they died, just that they weren't given enough of a backstory, which is something I like in my characters, especially if they have a major point in the plot of the movie. The main villain in the movie, Bethany, isn't believable as a teenager, and she isn't very sympathetic as a character. The ending of the movie seemed a little abrupt, but it wasn't a bad story.
Honestly, if this had been developed a little better, not only would it have been longer (it was only and hour and twenty-six minutes), but it could have had a lot more story to it and could have been a little more interesting. It wasn't bad, but it wasn't great, however it also wasn't the worst B-movie I've seen.