I was hosting my tileset with max resolution 320x240, and someone complained by saying the resolution was bad.
Even though it is "bad", single player levels in the original JJ style are SUPPOSED to be played in 320x240.
I mean ... Did you ever see the layer 8 for Labrat, Hell and Damn? They ARE made to be used in 320x240, especially the Damn one.
(4 giant mouths are ugly to see, 1 only is pretty awesome instead, and follows an actual perspective).
And Jazz is definitely MORE VISIBLE in 320x240, as you enlarge the screen.

I think the 640x480 resolution was originally meant to be used for multiplayer splitscreens. Is that so? Am I right or wrong?