The Connection is a first-person puzzle game set in a strange world of colorless cubes. Connect all the loose ends of three-dimentional puzzles to open up gates and travel further into the chaotic landscape. The length of the game varies greatly depending on how good you are at puzzle solving, I'd say an hour at max. Speedrunning is very possible, however you'll enjoy the game much more if you take your time and explore. The game was made in a week for Game Jolt's Chaos contest.
Standalone of The Connection for Linux. Inculdes two launchers, one for 32-bit and one for 64-bit.