I like the idea behind this game, but I don't think the execution was too great. It's waaaay too difficult to fight or dodge enemies since oxygen is fairly limited and attacks are costly (meaning it's not worth using it a lot of the time) but at the same time the player moves too slow to dodge, so any encounter with more than one enemy is pretty much a death sentence as far as I can tell. If you can figure out a way to make it more balanced in favour of the player, I think you can get something good, but it definitely needs a lot of workshopping.