Thank you so much for the review! ❤
The thing "if you'll die falling on rock or wall, you can still kind of survive..." is actually wanted, so it's not a bug. The meaning of this choice is that I think it is more interesting to make the submarine stop because engines no longer work than actually end the game.
Distorted sounds at the end happen because when the finish panel shows, it actually doesn't stop the game. So yeah, it's a bug.
Thank you again for the report!