Just watch for a few seconds as the waterfall slowly constructs itself and the music plays softly. If you're not perfectly satisfied with the way the waterfall is at the end, click the flag again and it will be better, as it is always slightly different.
Huge credit to "Monkey Island 2" By LucasArts games, for the idea and Guybrush who's hiding behind the waterfall at the bottom. The music is also from the waterfall in the original game. All artwork by me except the player (Guybrush). Basically, the way i programmed this is quite simple. It looks like the pixels are falling in a stream or waterfall, but actually i just created a bunch of clones of pixels that repeat through a process of different shades of blue, to give the effect that the stream is flowing.