Well it looks fine on an old CRT monitor of course. 640x200 was common enough (Amiga, Atari ST, etc.).
If it uses mc6845 then it's probably just 640 x 200 with 8 pixels of border color. There's a similar trick with a bunch of Sharp X1 games that isn't yet emulated (Shilver Ghost sets 640 x 192 during scrolling phases, also a Koei game does 640 x 8 (!) just to show a single line of characters and mask the rest)
