This is a neat idea. I couldn't get that far though (I think I got to level 3 or 4), because I couldn't figure out the nested repeat. It would be interesting to have some feedback (audio/error msg) in case something was wrong in the syntax.
That being said, I can only imagine how crazy it is to make all this programming syntax work within the game environment, so kudos for that.
Another cool thing about this is that I felt smart whenever I made a working solution. These kinds of game have potential (programming puzzles), but at the same time I feel they're tough to get it right. But good job!