I was wondering the same thing. It looks like it's not functional yet to me is all. I think the catapult is like a tactical missile launcher from supcom, and the base structure looks like the nuclear missile silo.
I build one and it pretty much behaved like that, yes. The trick is to build it close enough to your enemy to get it working.
It fires once every 6 seconds, but you need to be close enough to see them, and there has to be a line of sight. So if there is a butte or a mesa in the way, it will never reach.
Pretty sure "base structure" is placeholder for the nuke silo. Based off the look, shape and price. :lol: