I knew the oxygen part could be problematic in the game. but yet I wanted to add a little tension, initially, it was thought to run out after 5 minutes, which would give you more than enough time to even complete the game without needing any extra oxygen. I ended up shortening it for testing of death animation, etc, but, I didn't change it back the last day.
I had plans to add room labelling and a room floor map with colours at the start but since the map design changed during development it was not fit. It's my first ever Jam so Thank you, your feedback means a lot!