Wow, just wow. Such a polished game, and you did this in a week? Bravo!
I was a bit skeptical about the "Use headphones for the best experience", but I glad I followed the tip.
The art style and audio together made a very "deep water exploration" experience, which very much adhere to the theme.
The gameplay part is also very good, the risky and hostile aliens and environment gave the exploration experience a boost.
If you told me this is a game ready to be sold I would've believe it. There's a lot of game on steam that are less polished than this game. Great job!