You're extremely talented man, I've been following you ever since your AOT fan game and have just been constantly impressed and in disbelief that this is a solo project, everything about this blows my mind, I don't know how you can do it all but it's really impressive!
yeah, I think the UI could use a little bit more work, but its going in a pretty cool direction that I haven't seen before. It feels like a mix between traditional japance art and grafiti for some reason. I think you could push the brushstroke textures a bit more, and be a bit more graphic and selective with the colors, maybe only use 2 or 3 colors? right now they feel off compared to the ingame stuff as well, which is using a different color palette, (more primary) compared to the UI (more pastel looking). fish anims are looking amazing though!