This is really good. I liked the puzzles. I especially liked the secondary touches in the level layout, like how you could see the path of the water flowing between screens. For some reason that detail really struck me.
I think I hit a bug at the beginning of the mountain climbing segment. I was able to turn one of the grey blocks yellow but nothing I did seemed to have any effect on the first grey block you see and I couldn't turn the turbine. Maybe I just wasn't seeing the solution.