I experienced precisely this effect, in a before-and-after style, as a gameplay element yesterday. The game started with lots of visual detail, but began to "degrade" as you advanced through it, and at 100% completion every tile was replaced by a single-colored block.
A regular computer can draw red and orange squares and accept inputs from buttons too. If you really want to do a hardware project, get an Arduino, but you can easily play with ideas like this without any hardware. And you won't have to write your code in C.
It sounds like she may have some minor hearing problems, but I think your social disabilities probably have a much greater affect on you than her disability has on her.
