In order to help inform a future game overview page, I wanted to gather some info about what kind of titles (and crossover appearances) are known about so far.
Mahouka Koukou no Rettousei: Out of Order - an action game for the PlayStation Vita, due out in Japan on December 25 2014. It will have three game components: a VN-esque story mode, a 3D duel battle mode, and a CAD modification mode.
Mahouka Koukou no Rettousei: Lost Zero - a card battle RPG for iOS and Android devices.
Mahouka appearances in other games
'Dengeki Bunko: Fighting Climax - a 2D fighting game involving numerous Dengeki Bunko properties. Shiba Miyuki will be available as a main playable character, while Shiba Tatsuya is listed as a support character option.
Sword Art Online: Hollow Fragment - an action RPG based on the Sword Art Online franchise. A cross-promotion will see Kirito and Asuna costumes become available in Out of Order, and male and female First High School uniforms will be offered in Hollow Fragment in return.