The concept is interesting but the execution was weak. If they had extended the run time and played with the concept more it could have been pulled off but instead they tried to cram cheap cliches into a 80 min run time with an abstract location. Instead of using the cool concept to create something intriguing theres a lot of weird camera cuts and water movement. The scrip just feels lazy, the idea was there but a unique concept does not equal a great movie if conducted poorly.
The movie misses the mark on adhering to what makes a good movie, for starters likeable characters and a multi dimensional plot. The entire haunting seemed like it was written by a 10 year old, more zombie esc than anything paranormal as I was expecting, with what could have been an interesting backstory that was simply rushed over in the last 10 minutes.
I will say though that I feel a lot of these reviews missed the purpose of the "3 minutes" thing. The point was that she COULDN'T hold her breath for 3 minutes. The timer showed 1 min 22 secs, she lied and it ultimately screwed her in the end.