Update [Wed 8th Mar, 2023 17:30 GMT]: It's now easy enough to play SegaSonic Cosmo Fighters in MAME:
Original Story [Wed 22nd Feb, 2023 17:15 GMT]: SegaSonic Cosmo Fighters probably isn't a Sonic title many Western gamers will be familiar with. The AM1-developed spin-off launched in Japan in 1993, and for years, it was simply assumed that it was never localized into English.
As a result of this, curious Sonic fans hoping to track down and play the oddity had to make do with translating and emulating the dumped Japanese ROM on MAME if they wanted to see what we had missed out on.
However, in 2021, the Sonic fan IAMAMAZING100 announced they had acquired an extremely rare cabinet of the game featuring an English Dub and translated text. This was apparently used and operated at the in-door amusement park Sega World Sydney. Now two years later, they have not only dumped the rare ROM of the game but have also posted some new footage of it online for our viewing pleasure.
The roughly four-minute clip shows Sonic taking off in a spaceship before battling and defeating Dr. Robotnik. Besides its historical importance, what is arguably most interesting about it is that the voices of the characters are seemingly reversed, with Sonic and Robotnik having swapped personalities with no explanation as to why. Was it a mistake? Intentional? Right now, your guess is about as good as ours.
You can watch the footage featuring the bizarre voice acting below or listen to the isolated voice recordings here. Also, if you want to try and get it up and running yourself, IAMAMAZING100 announced that the ROM apparently already works in MAME (if you have some basic knowledge of the command prompt), but will hopefully be officially supported with the next update.