This one was made entirely in GIMP if I recall correctly. I used a photo of dirt as an overlay to get some texture. Lots of toying with custom brushes in this one.
As for OS I used 64bit Vista, I have like 100 games in my collection and I want to be able to install and play any of them any time I want as easy as possible. Otherwise I'd probably be running some Linux distro, I tried a few and liked it. I know about Wine btw.
SPARKLY! I love how you get so much detail in there with such a simple palette, just the blue and black there. It defies the laws of physics. Also, I didn't notice what was going on in the left foreground until I checked it on fullview again, subtle stuff like that really keeps me looking around. Awesome work!