interesting premise but the motives and actions of characters were sometimes left unexplained. acting was not that great overall as well.

An interesting take on the now-classic trap horror sub-genre, but where it excels in spinning some new ideas in a tired device it fails in delivering any sort of unique experience. The subliminal references to Cube and Saw are so blatant it's almost impossible to take this film seriously, but it's well-made and entertaining enough to watch at least once.

Serious masturbation material for math nerds and Cube fanatics.

Engaging thriller with a fairly clever story.

A pretty cool mix between Cube and math homework. Most of the reveals were good, and it's just great fun to follow the characters as they try to deduce what's going on. As with most films like this, the conclusion isn't as great as the buildup. That didn't prevent me from enjoying this, however. I might be a bigger nerd than I thought.

a decent spanish thriller that is generally predictable, or at least never surprising, in its unfolding. i have no problems with the acting or direction, and the whole premise is a great idea. watch it if you're looking for a decent, but forgettable thriller.

The plot is ludicrous and characters facile, but it's very nicely shot and the logic puzzles are fun if you're into that sort of thing.

"And while some of the in-movie puzzles are relatively obvious, the flick as a whole proves to be sort of a puzzle in its own right."

Interesting premise that fails to deliver a remotely satisfying conclusion. The suspense is pretty well executed though and the actors do a great job. Still leaves a lot to be desired in terms of the actual story which felt too forced and overly complicated to be believable.