I don't see what you think it's wrong with it, I found it fine. The idea is nice (to be fair all of your ideas are); the difficulty curve is alright and I didn't really found any issues with it. Accept from me.
I found no issues with it. This level is pretty fun, mostly challenging in the platforming side without relying in too much enemies, so props for that. I also liked your use of the non-water fish in a way that it doesn't overwhelm the player. I give it an accept, good job!