Extremely impressive. Very creative premise, and a huge number of levels. Clever interpretation and integration of the theme, "only one" minute of oxygen in your suit.
The game-play is surprisingly in-depth, the O2 meter being your health-bar and your movement makes things quite challenging.
The use of sound is also excellent, the ambiance adds massively to the eeriness and stress.
Minor bugs include the text for 'Chapter 1' and 'Chapter 2' not appearing for me, making the title screen a bit confusing. Also I floated through a wall in the room at the beginning of chapter 3.
Overall this is an incredible effort and I'm amazed that this was made in only 48 hours.
5/5 in all categories.