This is really cool. I'm especially inspired to think of the kind of gaming that could be done with that force - the kind of scenarios most of us can't do because, you know, we don't have a huge swarm of armed robot drones available to game with!
I'm starting to toy with the idea of emulating this project in some way that doesn't involve the scratchbuilding. Maybe just get 100-200 cheap hoverdrones from some manufacturer, or something. It wouldn't measure up to that swarm of scratchbuilt spiderbots, but it would get the job done from a gaming perspective.
This way lies madness. I'll have to file this idea away for later.