Fun game! I really like your particle effects, and everything feels very cohesive.
Suggestions:
- The first level felt a little too long to me, it might be nicer as a shorter tutorial level
- I like the fish powerups, but I wasn't sure what they did all of the time. It would be nice to show a little pop up of what a fish does when you get a new type of fish, or maybe even have a way to select the fish powerup you're going to use.
- It would be nice to have a fish power up slot counter, as I think I wasted some fish that I didn't have space for
Overall though I think you did a great job with this and the gameplay is nice!