Hey, thanks for trying the demo.
So oxygen will be a pretty big part of the game but it's not going to be used in all areas.
I will continue trying to improve upon this aspect over time and things will likely change a lot at some point.
Glad you like the puzzles as this is going to be a major part of the game, there will be more variation in the full game though as the demo is a bit repetitive at times.
Thanks for the feedback, glad you like the demo. :)