Superb! Challenging, cute AND informative
The one thing that nearly drove me crazy sometimes was rotating the tools - I confused Z and X too often. Pleeeeeeease if there's a sequel put some hint on screen... And also a warning that if you leave the last room before loading everything (my tool was inappropriate) you'll need to start again :\
Also, the difference in scale b/w the design screen and the "real world" confused me a bit, but this wasn't too much trouble.
Other than this, pure fun!