I will make a modded engine for wall heights to be interchangeable. The idea here is that each level is one unit high with 1 being the ground to 20 being the sky. To change levels and pen colors, B+D. To select one of 10 available maps, B+U. Move pen with gamepad and any selections will require gamepad. I made it as easy as possible.
Get LowRes Coder to use this program.