Love these types of films! But this one's a flop...
It's not the premise that sucked, I actually liked that, but there are too many inaccuracies and overlooked points for this film to work for me..
1. It's not hard to go 30 days without eating, in fact by that point you aren't hungry at all, and it doesn't hurt.
2. Nobody got thinner as the movie progressed.
3. Too many means of escape that nobody even tried..
a) Use bone/rock/metal to fashion climbing spikes
b) Stack the barrels and climb them
c) Fashion a hook out of bone/rock/metal to attach to the rope
d) Stand on each other's shoulders
e) Use rock/brick to smash hand/foot holds up the well
*) either option at the top feed the rope through the planks, pull to break, or just smash to *beep* with a brick
4. They honestly thought at after 30 days they'd be let free, but they cracked and turned cannibal on like day 25 lol!
5. Why wouldn't they use water/dirt to smear mud over the walls blocking any possible hidden camera's? They could make their tools in privacy.
6. Extreme bouts of immobility followed by rapid movement = impossible
7. Horrible and unrealistic portrayal of the progression of mental illness
8. Guys didn't grow beards..
Uhmmm... That's it off the top of my head, sure there's more so feel free to add 9, 10, 11....