Today Sega announced the “Project Needlemouse” they’d been teasing for the last few months to be Sonic the Hedgehog 4: Episode 1, a 2D game with 3D modeled visuals. Via an interview with GameSpot and a website loaded with time-locked menu items, Sega’s breaking the silence on their new downloadable game.

“Needlemouse” being the code name for Sonic when the original Genesis game was being pitched, most folks expected a Sonic game of some sort.

As it happens, this game is reported to return to the series’ roots with Sonic as the only playable character. Picking up after Sonic & Knuckles, as indicated by the “episode 1″ in its name, this will be a new and ongoing story arc for the hedgehog.

Associate brand manager Ken Balough told GameSpot, “As mentioned, I think the best way to view it is as a first part in a much larger adventure. When Sega released Sonic 3, ultimately it was the part 1 of a story that saw its conclusion in Sonic & Knuckles. In that same spirit, Sonic the Hedgehog 4 is a bigger story, and this is that first chapter. I think it’s also safe to say that by the end of the episode one, fans will be very excited to see what’s in store for episode two!”

While a firm date hasn’t been announced yet, Sonic the Hedgehog 4: Episode 1 is slated for release this summer for PlayStation Network, Xbox LIVE and WiiWare.

Meanwhile, check out the teaser trailer from Sega and get ready for what could be a great return to form – something we’ve said about a bunch of Sonic games before now, so let’s not get our hopes up.