Halo: Spartan Assault will be released today exclusively for Windows 8 PC's and tablets and the Windows Phone 8. Spartan Assault is a new action shooter set between the events of Halo 3 and Halo 4. This new chapter has you experiencing the first missions of the Spartan Ops, diving deeper into the back-story of the Human-Covenant wars. Battle through the eyes of either Commander Sarah Palmer or Spartan Davis set aboard the UNSC Infinity as they fight outstanding new battles against the Covenant forces.