Really cool game here, did great on the calm! The music is great too, I assume you wrote it.
Sprites and animation are on-point, I love the use of dithering to make such interesting backgrounds out of like 2 colors! Definitely had some collision mask trouble--while I got used to the player collision being big, the jellyfish masks' corners were brutal and sometimes caused frustration. Otherwise the game had no other bugs and was extensively polished for a game jam!