Oh boy! I love playing games!
This game's really good! To give an example of how much I liked the game, I actually reset the game because I forgot to pick up one of the coins and wanted a perfect score!
Your protagonist reminds of the old ZX Spectrum mascot "Horace", not sure if that was the inspiration but I certainly got that vibe from him! So there's a SMALL bit of bias involved in this since I like the concept of him.
However just because I have a love for a now forgotten mascot doesn't mean the game is perfect, your biggest error in my eyes is that I don't really even see an attempt at a twist. It can't be the water, because that's in the title, it can't be the coins either, because it's being a point of the game for extra points. Shame too, aside from that. This would be a frontrunner!
-R.C. from Duppy Games