Sega has made the slightly strange but undoubtedly popular decision to build an emulator for its Genesis hardware, which most in Ireland would likely have known as the Mega Drive.

Shiny has already released Earthworm Jim for Apple's App Store.

Apple has taken issue with those emulators that have been submitted to its App Store up to now, with most being caught by the infamous App Store Approval Process and those that squeak through taken down shortly afterwards. Of course, those tend to have been unofficial efforts, which makes Sega’s offering for the iPhone and iPod Touch something a little different, moreover, it seems that Sega has essentially established its own precedent, in a way.

Sega has already been selling a raft of its old Mega Drive games through the App Store, generally those that proved particularly popular on the original console itself, including the iconic Sonic the Hedgehog, Golden Axe, Ecco the Dolphin and Shining Force.

Gizmodo points out that the big shift that’s made all this possible is Apple allowing for users to make purchases directly from within a downloaded app. In Sega’s case, this means that users will be able to boot up their emulator, to be named Ultimate Genesis, and then use its own internal shop setup to buy some of the popular games of yesteryear, encouraging public-transport nostalgia to an extent otherwise almost impossible.

It’s certainly interesting to see Sega getting into the emulation business in an official way, especially given the long-standing interest there’s been in Mega Drive emulation on just about any platform that can manage to emulate the hardware. For now, there’s no word on a European release, though we’d expect it to come not too long after the US, given that this is an official one.