It looks like Treasure's rather marvellous Dreamcast and GameCube shooter Ikaruga might be on its way to Xbox Live Arcade.
That's because the game is currently showing up on Partnernet, the Xbox 360's closed debug network, access to which is limited to journalists and developers.
There are two downloads listed in the Xbox Live Arcade section of Partnernet, which mirrors Xbox Live's functionality in a different setting. The titles are nondescript, but if you download the two 5.7MB files Ikaruga appears under a Japanese name in the console's Live Arcade menu.
We couldn't get it to run, but it does reach a Treasure title screen, and lists 12 achievements including one marked "Secret" and one for each of Chapters 1-4 and the Final Chapter.
Treasure has previously said it was "really interested" in working on Xbox Live Arcade, but when company president Masato Maegawa spoke about that desire recently he wasn't specific about any projects in development.
Treasure is known to be working on an original shooter for Xbox 360, but last we heard it won't be out for a while.