It’s been teased for a month now and we even told you that it was coming out today, but now we can tell you officially that Halo: Spartan Assault, is live in the Store for Windows Phone 8.

Building off of the hit franchise and 18 months in the making, Halo: Spartan Assault is Microsoft’s attempt to capitalize off of the famous first shooter game for mobile. Instead of just “porting” the FPS model over though, a paradigm that is difficult to translate onto tablets and smartphones, Microsoft and 343 Industries opted for a third-person overhead view, which is more arcade style. The game’s timeline takes place in the four years between Halo 3 and 4.

In addition, the developers spent months honing game play to make the frame rate as high (and smooth) as possible and just as importantly, ensured that the game controls were fluid and flexible. From our last 24 hours playing with it, we can confirm that as a “casual gamer”, we found the game highly accessible and extremely well-polished.