the idea be interesting and the movie be ok at the beginning and then it go downhill . i mean and it turn boring because it be the same we have see a million time represent a group of people where an unknown entity kill the others one by one . also the character be not particularly likable so you do not care if they be kill or not . character development be very important but the writer do not pay too much attention to this so each person mean the same to you . the movie have some good chilling moment and but it be that kind of flick only enjoyable by teenager . by the way and there be some cheap sfx at the end that make you laugh .