I think I see what you're talking about. I tried to add some anti-aliasing to the sprites as well but I couldn't figure it out.
Apparently I can't run most games with my VM (Win7) due to missing libraries (it seems it can run old games like Higurashi but not GameMaker games or my own game), so I used Wine. If I can get the VM set up (I hadn't used one in over a year and just installed it for the hot-fix) I'll see if I can run it on it.