Wow, this is really a good game, congratulations, you can be proud of it. I had to give up for the moment in the level where I have to run up the rotating black rod (tree?), that one does have a certain frustration factor. Might try again after a good night's sleep. No idea how much more is to come, but it is amazing already how many great puzzles you could realize with your basic mechanics.
I think I also ran into a game breaking bug when the confirm dialog was open while I died - the level restarted, the dialog was gone, but I didn't get controls back.