Thank you.
It's not being used in a real-time environment. It's being used as an illustration. Remember how in Master of Orion whenever you got a new research item, an image of the item would appear? That's the point of these images, generally.
Is the cannon finished? Eh sorta. The modelling's done. It could use a little extra texturing, but it's more or less renderable. I don't have an environment for it so I haven't done a 'final render' of it. (I'll have to address that before too much longer, though, as my demo reel will start cooking soon.)
I intended to build an environment for the cannon to work in, but alas, time was against me. Eventually...