I'm sensing a theme among negative reviews: that this is a SAW rip-off without the gore. As much of a sweeping statement that is, and how little credit it gives to this movie, I can see where they're coming from. I was always fascinated by the small amount of psychological horror in the SAW franchise, but felt like it was too much of a gorefest to truly be able to appreciate it.
On the other hand, "Die" takes all of the elements I had wished to see in SAW and uses them full-force: there's the murky morality, the inescapable desperation, choices that don't feel like choices. "Die" is violent, but it is subtly so, and focuses a lot more on the characters and what they're going through. I found it incredibly intriguing and entertaining. The acting was good, the cinematography well-done--overall, I was impressed.