A criminally intense thriller.
The Oxygen levels are especially ingenious. You really do have just baaaaarely enough time to get yourself out of there, and it's almost impossible to do it with Dave still alive. It's just a great application of organic choices.
However... uh, after my fifth try, I finally got Dave to safety... but the epilogue still said that I lost him on the way. What?
Also, I'm shocked to say that I'd actually prefer some overdone minimalist Atari graphics over what we were given here; or at least, a much darker backdrop to match the heavy and desperate theme.