Dimensions are based roughly on the SNES controller, that was the design guideline. I kept it modifiable for some reason, there's a part of the back cover board that can be cut out and the 2ndary components are connected to the arduino by bits of female header. Usability was a secondary concern to beauty, this is not the right way to make a gamepad, but it turns out very usable. I'm really happy with the functionality. It feels good in the hand, too, i love the texture this kind of papier mache creates.