I like it and I love the concept and I love almost everything about it! But, I have a couple of things I would like to critique on it.

1. It's short... Some more content could and should be added.

2. This isn't exactly teaching much about programming. All it is is changing variables, with some code that the player can choose to ignore, as it isn't explained and isn't really necessary to win the game. Something like Code Combat* or Hour of Code** do great jobs getting the player to interact with the code and teach the concepts without being boring long lines of code. The difference with those is that they aren't highlighting variables etc. and they can also very brand / advertising overloadng or have too much pre-made code. I like this idea though.

All I have to say is; great concept, great game! Have a nice day!