Finished this game last week. It was really good. Took some time to get all of the endings, but you can easily achieve a platinum trophy in one playthrough. I did get kind of puzzled out at the end and started relying more on the game guide for the puzzles, but meh…
Since the game links back on itself, it’s extremely difficult to explain without spoiling it. Pretty much you are Sigma, an amnesic who wakes up in an elevator with a weird watch strapped to his wrist. After each puzzle you solve, the characters vote to either ally or betray each other and the groups will reshuffle. If you get 9 points, you can leave; 0 points, you die.
After that, you’re trying to figure who’s trying murder whom and how you ended up like this. Would totally recommend it to visual novel and puzzle game enthusiasts. The graphics are dated and there is strong language and light gore.