Specifically, we acknowledge that the results from Fig. 5 are from a very small sample set. Evaluation plans include testing with students ages 4-9 to determine if there are differences across these ages with respect to the engineering principles being taught in the tower contrasting levels. There will be "pre-tests and post-tests" given bracketing the game as well done here, to establish whether the game promotes learning outside of the game itself. Of course, the game will be instrumented as well with robust logging and in-game assessments that will document the achievements that take place within the game.