This was the first thing that struck me as well - just fantastic level/game design. Immediately brought to mind the instructional level design from Super Mario

This was the first thing that struck me as well - just fantastic level/game design. Immediately brought to mind the instructional level design from Super Mario Bros - http://www.theoryofgaming.com/gold-standard-for-game-design/ http://www.theoryofgaming.com/gold-standard-for-game-design/