Thanks for the tip, Stijn. Looks like it was easier than I thought it would be.



Here's a demonstration of the dark fog I mentioned earlier. Like I said before, this actually has lighting set above what would be normal, as there is no "bubble" of light around Jazz in this screenshot (the light right where Jazz is present is the trail generated from holding down the Run key). The transparent black tile in the foreground darkens the entire scene to give the illusion of darkness, while the transparent white tile in front of the backround renders it as if it had a heavier layer of fog in between it and layer 4. The blaster projectiles shown here also give light still, so the illusion is complete.

I've tried using different kind of lighting events to see what would happen, and Flicker Lights have a particularly interesting and somewhat realistic effect (not shown here): the fog appears to flicker a bit.