It's done! Actually it would have been done a lot sooner (this is why you got a preview) but I managed to hurt my hand a bit after working extra hard on it the second day--I hold my stylus pretty tightly and after working for so long without a real break (once I get going on something like this it's hard to stop!) it started getting to me, I figured I'd better quit before I did some real damage.
Anyway, here's my latest Sonic picture! I like drawing the backgrounds so much I didn't even bother putting Sonic into this one. Thanks a lot to everyone who commented on the preview picture, and I hope you like the full version even better!
I'd like to do a second piece (making it a diptych!) showing the "city" levels, but it won't be for a while--focusing on my own non-fanart projects really takes priority! Thanks for looking everyone!
I've often thought of these three levels as a "set", with the other three original zones as the other set. Granted, Labyrinth Zone was originally going to be the second Zone, between Green Hill and Marble, so maybe whoever designed the level concepts had a similar idea.