Somebody ported Word War vi to the vectrex or to some souped up version of a vectrex with custom vecfever firmware.
Here's a video of it: https://www.youtube.com/watch?v=BzU1_V6AjyA All of the color is coming from a cellophane overlay on the screen, the hardware itself is just black and white.
I think Word War vi is the most widely ported software I've ever written, it runs on x86 (of course) but has been ported to ipad, OpenPandora, and now Vectrex.