No, you're not still hallucinating from that food poisoning you got after eating that six day old Christmas turkey, this really is Sonic the Hedgehog (and his pal Knuckles) appearing on the PlayStation Vita.
The classic Mega Drive (or Genesis, for our US readers) title appears courtesy of a game of Russian Dolls - emulation-stylee. The action is an emulator within an emulator you see - the PSP one that comes on Sony's latest handheld, combined with the Half Byte Loader running the Picodrive emulator.
It's not likely that you'll be able to get Sonic & Knuckles, Altered Beasts, Golden Axe, James Pond or any other Mega Drive favourites on your PS Vita when it hits UK shops next month though - Sony has the ability to close up this exploit via an update.
Shows what might be possible in the future, however. Let's hope they sort the sound issue out though....
Check out our First Look: PlayStation Vita review