I'd actually been kinda looking at these after the other televideo keyboards with space invaders showed up. I could tell from one of the pictures of one with missing switches that they weren't space invaders because of the positions of the missing legs, but didn't know what they were other than guessing they would probably be linear given their choice of linear space invaders in the other ones.
That looks badass. Can it be modded for PC use?
AFAIK, if you do a controller swap, any and all switches that work via contacts of some kind can be done in the same way. The other linked geekhack page is another way - just using the plate and pretty much throwing away the PCB and just hand-wiring the entire matrix direct to the teensy.