i made it up to the purple fish, and a little past that i think! not quite to the last fish, so i have a goal for next time :)
ahh, physics. i understand, lol. red fish could come later for sure, or maybe the different fish could be sorted into difficulties? it does depend a lot on the level which fish is easier, but something with that could be fun. where you get some sort of reward depending on which fish you beat the level with (this could also tie into encouraging the player to experiment with different fish). and the dead fish are usually fine, i just have issues with the orange ones for the most part. maybe after a bit they could dry out and lose their stickiness, falling into the water below?