I was playing a bit of AirBuster today, and I found a hidden X68000 machine in the background of the first stage.
Check it out:
(http://nfggames.com/grafx/X68000.png)
That's hilarious. This is the Mega Drive version? Or was there an X68000 version of the game?
Sorry, I should have mentioned: It's the arcade version. I was looking for backgrounds for a friend's project, and was digging through the first stage with mame's tile and background viewer, and there it was. At first I was like O_o? and then I lol'd. =D