I took a screenshot and converted it to 2x2 (it only got 32 colors. would
look better with 256). Then I masked it like it's done by blitterscreen.
Imagine that beeing a screenshot of a clone running on A1200 :)

IMHO possible at quite high framerate: this amount of pixels is done
at about 10fps by texdemo57 on a A1200 with fastmem.
In more dungeon-like rooms that need not that much z-stuff calculation
etc. it even does 15fps. The time needed for c2p was about 20%.

So let's imagine there would be a chunky 256 color 2x2 screen needing
almost no cpu time ;)

result: 1/(1-20%) * 15fps = 18fps !

playing a game with gfx like in the pic in 18fps on A1200+fastmem,
a crazy thought ? who knows...