I played all the way to the end, and had a lot of fun though I am embarrassed to admit that I spent most of the game thinking that "Oxygen resistance" was one upgrade with 20 levels that I couldn't decipher the meaning of. Even worse, I didn't realize I could steer the diver until almost the very end, I spent most of the game just letting the diver go in a straight line from where he landed.
Overall, great entry and tons of fun, especially for only 2 days of development.