This is a screen shot of the menu to Arcade Gamer Fubuki. It's an anime...but look at the sign in the background! That's clearly SA1 'looking out' Sonic there, among the crowd & bright letters. You can also see that the menu seems to be written in a font quite similar to the Sega font, & the word 'previews' is written in PacMan style letters. It makes sense for Sonic to appear around arcade-centric imagry.