I put this into DMU, because I've not played that game for ages, and, frankly, I wanted to make a rather audacious return. It's become a shadow of its former self. Little more than a silent lane for view whores to get a few hundred punters.
Whereas, of course, DMU should be far cleverer than Mornington Crescent.
There was a spin off. A Normal digital numpty said, "Don't like those top two corners". Which alerted me to them, and to the possibilities of vignetting, and maybe the physics of it. Isn't the top left corner an echo of the top right? Or of the dark bottom right? OR (and this is the really interesting possibility): Are all the corners echoing one-another?