Thanks for the comment !
I see what you mean about the pacing. During development I thought about it and had the idea to add a save/checkpoint near the bottom of the map (a bit like how generally games auto save just before a boss fight so you don't have to redo all the walking/other tasks that led to it and can focus on developing a strategy to beat the boss). I unfortunately did not implement it but I think this is the right solution. Especially in the current state of my game I think it does not help that you have to reload the page and redo the "tutorial" at each try.
Audio also is something I would have liked to implement if I had the time because I feel it could really have helped with the ambience and complemented the visuals.
I think I'll try making a post jam version and those will be the first additions to the game. The next additions would maybe be some more content. I'm thinking about exploiting the "dive outside the submarine" mechanic more, maybe having to go through a tight tunnel and look for something in there, I think this could be great, with the pressure of having limited oxygen.