This is one of the prettiest games so far! I really like the idea. I think that the water should show it's flow a little more (for examoke some wave particles/shader stuff) and pushing the player down a little so it looks like he is affected as much as the other objects. Also it kinda does not make sense to have stones flowing down the river, so at first I was unsure if I was going down the river trying to avoid stones or the stones were coming at me. Overall very nice, I like the approach to the theme