Fermat's Room (2007)
Three mathematicians and one inventor are invited to a party by a man who calls himself Fermat. Their host excuses himself and the group finds out (via a PDA) that they must solve a series of mathematical riddles within a given time limit - as the walls of the room slowly close in on them.
Nine Dead (2009)
The film opens with several different people all getting kidnapped by the same tasering, masked man inter-cut with said masked man preparing a room for his captors. Nine people are each handcuffed to a pole and told that one of them will be killed every ten minutes unless they can figure out why they have all been brought here.
Now I love movies like this. Minimal locations and minimal characters just seem to be more intriguing to me... IF they are done right. Two of the above movies get it right, one doesn't. My favorite was probably Exam, followed very closely by Fermat's Room with Nine Dead just way off in left field, almost not even worthy of being close to the other two.
But more than the characters and the story, I loved the riddle presented in Exam. They have only one question to answer but there is no question on their paper or anywhere else in the room. The rest of the film is the people using several different methods to try to read the paper. Is it infrared or ultraviolet light? An ink that reacts with chemicals? When the question is finally found, the solution to the riddle can be interpreted two different ways (trust me, I've seen endless discussions on IMDb about which one is right) but either way, it's a good one, and one you might be slapping yourself in the forehead about because of how obvious it was.
I tried figuring out the math riddles the characters are given myself for about ten seconds before I realized they were just zinging over my head. I liked math in school and all... but not THAT much. The real riddle is who their mysterious host Fermat is and what these people have done to deserve this treatment. I liked this movie because there was real suspense with the moving walls and less characters involved - and therefore to keep track of - than in other films like it. They each have their own little secret, of course, and you may not like some of them later on, but with so few chances for survival you need them all to live so the good ones can get out. Highly recommend this one. It's a quick, fun, interesting little thriller with a plot that will keep you watching eagerly until the very end. It's also a Spanish movie, so you can impress your friends with that. Or something.
The acting really wasn't all that bad, even by Melissa Joan Hart, but nothing stellar either. There is a fair amount of action to keep you mildly interested to get to the conclusion, because there is an intricate web of riddles to work out how all these people are related. Again though, when the web is detangled it's not as big a deal as you think it's going to be. I say thumbs down. You can skip this one.
So there you go! Would definitely recommend Exam and Fermat's Room, but Nine Dead does not come up to par. Time is obviously an important element in all these films, and you can only go so far with a few characters in one room before it gets boring. Thankfully, all of these are right around the 90 minute mark so you won't waste too much time.
And tell me about any other movies like this! I really dig 'em, I'm tellin' you.