What an awesome project. It looks fabulous!

Reminds me of the Dato Duo I have.

The "Dato Duo" is also a synth aimed at kids. It allows 2 kids to play together. it is made by a Dutch company called Dato (https://dato.mu). Their latest musical invention the "Dato Drum" had a successful Kickstarter and is shipping now. This drum machine allows even more kids to play together.

PS: As the owner of a Dato Duo I can share you a little secret: it's also fun for adults :)