Apart from the few missed notes towards the end, you have the piece in your hands, technically speaking. Now you have to make it sound like a "waterfall", as you,called it. Another nickname i wasn't aware of...at any rate, to make it sound like a waterfall, you need direction in the phrasing. It barely sounds like it's going up and down. It's flat-colored. like a metronome. And there are a few places where you can do a slight ritardando or stentato. Like before the reprise.
It's funny how a difficult piece like this can pass as a minor etude when you don't do anything with it, musically.