I think it could have used better directional indicators or some breadcrumb mechanic as it was very easy to get lost/go in circles which was really annoying given the slow movement speed. I think the bubbles could have returned more oxygen as well, just camping on the bubble spawn to fill up was a bit aggravating. Those things aside I really liked the overall atmosphere and how the story unfolds and the oxygen mechanic created a lot of apprehension at times. Great job!