I'm working on something similar, but 3D and faster motion: PinThing / TAP (Tangible Actuated Pins) [1]
"Motorized pin art display" is what i'm going for...
The problem with passion projects: Progress is never as much or as fast as I want, though! Hard to find the people who want to throw money at things like this and/or buy them. And anything mechanical gets complicated and expensive very quickly. But it's so much fun and a great way to learn and apply so many new skills: laser cutting, 3D printing, CNC milling, circuit design, embedded programming, etc.
I love this so much! Will it be mounted so that gravity makes the pins fall back down or do you need a retraction mechanism?
it's all motorized, so it can be wall-mounted or table-top mounted.