Thank you :) Your comment is really nice! I'm not really proud of this game because of the pixel art, I learn pixel art right now. Actually, I've only been making games for 4 months. But anyway, I enjoyed doing this game! You're right, the gameplay is a bit tough but I didn't want to have too easy game, it's a nightmare :). I take your observation about health tool into consideration, I'll make some update this way...
Yes movements are blocked, maybe it's better to not block them. You're right, the oxygen consume rate difference is not visually obvious, I have to fix this.
Why do you think it doesn't work ? Consuming less oxygen doesn't mean that oxygen won't decrease anyway, it means oxygen will decrease less quickly. Of course the game needs polishing, I will have time for this now ! :)
