How to build a button box for a toddler

The creator of the CodeParade video channel made an interactive pushbutton busyboard for his toddler.  He bought a bunch of knobs and switches, wired them to an Arduino, LEDs and beepers, and put them in a craft box. It has a simple mode, in which pushing a button triggers a sound or light, and an advanced mode, which includes a Simon game. It looks like something people of all ages would enjoy playing with.