It's pretty awesome. I only noticed a few things.
One: There are no stones on the dirt paths around the stream after the waterfall, or around the path.
Two: There are no stones/bubbly things in the shallow water
Three: Things in red squares
Top Square: That one flat piece looks weird, It can be fixed, but that whole left side of the stream will have to be re-edged with shallow water to make it fit.
Bottom Squares: Where shallow water meets cliff is always troublesome... Don't be afraid to make a custom image for it though!
Copy all of the shallow water edge tiles into an image program, and remove all of the dark blue. Place all of the half transparent tiles into one big image. You can use setimgpart in an NPC to make these spots look much nicer.
EDIT: Aw, hell... Here, I made one you can use.
Four: That dude with the mask is uber fugly. Wtfs?
Rofl<3