The block function diagrams would be clearer if they were stacked like they work instead of being turned on their side. That is,

    ▥ ↦ ▥ ▧

could instead be:

         ▧ 
    ▥ ↦ ▥

I hope that makes sense!

Also, the dropdown menu for levels could be replaced by something more informational (perhaps a tree control?), that indicated e.g. by color which levels have already been solved.