Loved the sharks and killer whale explaining the game to me :D
I like the idea of protecting the minnow but I kind of wished I could carry him like in the thumbnail! My first instinct in level 1 was to do so, but then I knocked him off course and learned I can't do that. Then I shot all the sharks and had to wait a while for him to get to the end, so it felt like I already beat the level but had to wait. I appreciated the fast forward button though but perhaps the overall design could be tweaked to change that wait period somehow.
Overall really nice, I liked the water animation and pixel art design for the fish/sharks!