Thank you so much for your feedback!
I really worked a lot on it during those 10 days. Some general systems, like the save/load system, were premade from my own library (since the rules said it's allowed to use them as long as they aren't gameplay-relevant).
Maybe I need a stronger visual indicator to show you're running out of oxygen, rather than just playing two sounds (one at 50% and another at 25%). However, the main idea is that you have to make a risk/reward decision: do you spend more time looking for a treasure, or is it better to bring back what you already have.