I think you can buy premade LED grid arrays. I would take one of those and overlay one wire per row, one per column, in tension and suspended a few mm apart. Yo

I think you can buy premade LED grid arrays. I would take one of those and overlay one wire per row, one per column, in tension and suspended a few mm apart. You could use a translucent 3d-printed framework to stabilize the wires and have a flexible piece above each junction to act as a button. Not sure how to make it click...