Gosh, I really love the idea of building the level as you go. I think I would side the rocket as a boast and make it more tetris style level builder. The only thing I saw that was a major bug was the level builder doesn't adjust to the left and right with the player. Minor improvement would be coyote fly time, there were times where I let go of space bar a little earlier than expected and it just cut off right there causing me to fall to my doom.