Here I will count down the top ten mystery/ thriller/ horror movies featuring group isolation in a small space where the victims have to play a game to win/ free themselves/ stay alive. (In order from worst to best.)

10. Nine Dead (2010) 3/10
A typical mystery thriller where nine people are handcuffed in a room and advised one will die every ten minutes if they don’t find the reason they have been brought together. The usual stereotypes: angry black guy, old white guy, cocky Italian guy, and also the not so common characters: gay pedophile and intense lawyer lady played by the one and only Melissa Joan Hart. Felt like I was watching an NBC drama.
trailer: https://www.youtube.com/watch?v=B0D9yqV3Aas

9. House of 9 (2005) 4/10
A generic group of “diverse” people are locked in a house and forced to ration while they wait to see if anyone will win the cash prize and be the last man standing. A little cheesy and humdrum but well-paced with a twist ending.
trailer: https://www.youtube.com/watch?v=YqH-ZpPNPNs

8. Unknown (2006) 4.5/10
A sausage fest of B-list actors are stuck in a warehouse and slowly regain their memories, ultimately trying to decide who the bad guys are. It’s crippled with boring monologues, but the second half is full of little twists and although they aren’t shocking or dramatic, they were fun to watch unravel.
trailer: https://www.youtube.com/watch?v=R_5Yh17oDOE

7. The Killing Room (2009) 5/10
It’s really hard to get past Nick Cannon’s ridiculous piercings, but this film about a few test subjects being watched and evaluated by the government has a great backstory to hide its bland characters (not to say the acting is lacking).
trailer: https://www.youtube.com/watch?v=VoqAszG5EYc

6. Fermat’s Room (2007) 6/10
This Spanish thriller is about four mathematicians who are brought to an isolated location to solve a puzzle, but instead they find themselves rushing to figure out enigmas and connections before they are squashed by a shrinking room. Even though this was not a horror and I had a feeling about the twist from the start, I found this entertaining and I enjoyed all the secrets revealed.
trailer: https://www.youtube.com/watch?v=SJ9y4SCLvNc

5. Would You Rather (2012) 6.5/10
A dinner party to die for, where the guests must play a gruesome game of ‘would you rather’ to earn a cash prize. The claws come out as strangers have no problem receiving the pain or deferring it. Really gory, but the idea of it is fun and the tension is high. Nice little twist at the end.
trailer: https://www.youtube.com/watch?v=it5XICr93wU

4. Exam (2009) 6.5/10
This little thriller-mystery from the UK does an excellent job of character building right from the get-go. It’s about potential job candidates who are given a piece of blank paper and a set of rules and told to answer the “question”. It’s one of the more original ones for the genre and it’ll keep you alert with its consistent pace and excitement.
trailer: https://www.youtube.com/watch?v=bkdt2Sygew0

3. Devil (2010) 7/10
Strangers are trapped in an elevator with the devil, but are unable to tell which of them is possessed. The lights go out, and one by one they die until only good and evil are left. A fun little ‘guess who’ mystery game.
trailer: https://www.youtube.com/watch?v=C7l3nzjHYTg

2.The Cube (1998) 7.5/10
This film and its sequels come from Canada, and can be described as a rubix cube mind-fuck where strangers with different skills have to navigate through a giant cube full of rooms set with killer booby traps. It’s pretty ninetiestastic watching it now, but it’s timelessly creative, nonetheless.
trailer: https://www.youtube.com/watch?v=MY5PkidV1cM

1. Saw (2004) 8/10
The first installment of the horror series takes place in a dirty bathroom in a warehouse and has loads of twists. Two men must prove that life is worth anything to them (and will probably have nightmares for the rest of their lives about that creepy mask.)
Full Review here
trailer: https://www.youtube.com/watch?v=HKPy5RWuqNA
Seen all of these? Also try:
Vile (2011), Are You Scared (2007), The Experiment (2010), Death Tube (2010), Breathing Room (2007), Hunger (2009)
New!
The Circle (2015), full review here
The Belko Experiment (2016), full review here
The Clinic (2010), full review here