I love these sort of trapped / survival movies, like Frozen and Open Water. But I found this movie to be flat. The setting didn't convey enough terror. The hallucination scenes were more annoying and confusing than interesting. I didn't quite get the backstory between the sisters.
Most of all, the main draw of these sort of movies involves creative thinking about what the characters could do. For instance, the viewer can have a lot of fun speculating about, "what if the protagonist does this or tries that to escape etc." Movies like Frozen and Open Water have that effect on viewer. This movie doesn't. More scenes should have focused on the characters' trying to get creative and find ways to stay alive.
Most of all, the main draw of these sort of movies involves creative thinking about what the characters could do. For instance, the viewer can have a lot of fun speculating about, "what if the protagonist does this or tries that to escape etc." Movies like Frozen and Open Water have that effect on viewer. This movie doesn't. More scenes should have focused on the characters' trying to get creative and find ways to stay alive.