The game will adopt the world of A Certain Magical Index with the protagonist, Toma Kamijo, and various characters such as Index, Accelerator, and Mikoto Misaka will pilot the mech Virtuaroids that will happen within the Academy City Setting.
Sega promises that the game will adopt the high-speed action that has been a staple of the Virual-On series. And that they will “use the experience gained in developing the series and maximize it” for A Certain Magical Index. Also, the special abilities of A Certain Magical Index characters will be amplified as they pilot the Virtuaroids.
So far, what we have is the trailer of the game as seen above.