Fun puzzle game. I think I needed the controls explained to me (it took me too long to discover that I could delete an object by dragging it off screen lol). Also, I would have liked a reset button for the level. I also hit a couple of physics bugs. 1, slightly changing object positions would sometimes influence the ball at the start of the level, ie I would change the position of a plank later in the level and then suddenly the fan would blow the ball differently at the start of the level. 2, at one point the ball hit a plank and just stopped dead, even though the plank was inclined.
Overall very fun game, and I think it has a lot of potential for more contraptions, etc.