It's a very nice challenge! To open the chests I first thought the way would be to drop something on top of them (which seemed to be suggested a bit by the environment), but I had more luck throwing them off of cliffs. On my first run I got stuck in the (\/)-shaped part, but on the second run I made it to the top. In the beginning it indicated using the spacebar to fly, but later I found that W worked too and I preferred it for this game, so it would be good to point it out also.