1. The puzzle was good, though it's hard to judge when there's only one available right now.
2. I'd definitely like to see some puzzles that revolve around the lack of gravity, both for navigating around and for toying with floating objects.
3. The O2 meter feels balanced.
4. The fire extinguisher is painfully slow, especially since you can't do anything in a room until the fires are out.
5. The game is incredibly short. It needs more rooms and different ways to interact within each one, especially if you're still planning on the whole branching endings/routes thing.
6-8. The game is quite rigid right now, forcing you to do things in a precise order before it lets you progress. It's also got a fair number of bugs, such as doors taking your power but not opening, being able to rotate the camera upside down, parts of the door arches are z-fighting, and the escape button can be pressed over and over.