This was a great start and a fun idea but i found i never needed to go to the health center and once I realized the building in the middle of the map with the big arrow pointing at saying it's the oxygen machine isn't, that part became a pretty simple loop. Movement input wasn't normalized so it's faster to move diagonally than orthogonally and so the enemies can't really catch up. Personally if I have to choose between juice while firing and juice while hitting/killing enemies, the latter is a little more satisfying. Loved the atmosphere (no pun intended)!