I was expecting a "so bad its good" movie .. kind of like an amateur-ish attempt at horror with bad effects, poor acting and run-of-the-mill story. What i got was a movie that both confirmed the bias/expectation and also exceeded it.
The acting is below average .. there is little to no subtlety. It is a ride of extreme emotions and a bit of over-acting. There are non-essential characters that .. sadly are also treated as such (red shirts) - a stereotype that could have been averted without harming the plot.
There is good .. what i think .. practical effects. and absolutely TERRIBLE!!! CGI that looks like it comes straight from the Playstation 2 (and i really mean it). This is especially sad because some of the practical effects are really, really well done. Had the director (or whoever decides that stuff) decided to use the lights/darkness .. and use practical effects (in that case silhouettes rather than to show everything..) it would have improved the movie significantly.
There is good pacing .. in what is otherwise a predictable and simple story.
The conclusion .. is a bit surprising - for the movie does not follow the usual tropes for an ending of that sort of movie.
All in all, this movie is well worth watching