Makoto Asada is developing an unannounced Xbox One game at Mages/5pb, having left his job as head of shoot-em-up specialist Cave to work on the next-gen project. Asada moved on from Cave back in June after five years at the studio, having helped produce Guwange, EspGaluda 2, Akai Katana, and Deathsmiles among plenty of other games.
Details on Asada's Xbox One game are sparse, but Dengeki Online (via Gematsu) does report it'll be packaged, and that more info should be forthcoming shortly.
Mages also announced it's publishing Constant C, a 2D action-puzzle game that was one of the 100 recently Greenlighted on Steam. Mages is bringing Constant C to Xbox 360 as a downloadable game in early 2014, although it's unclear if that'll be limited to Japan or not.