Ready up fellow Spartans with Windows 8 on their PC’s, Laptops and Mobile Phones – Halo Spartan Assault launches today as confirmed by Xbox UK’s Graeme Boyd (Social Marketing Manager).

Halo: Spartan Assault releases for Windows 8 and Windows Phone devices today. Played it at E3 and it's great.

— Graeme Boyd (@AceyBongos) July 18, 2013

Halo Spartan Assault has 25 unique missions featuring unrivalled action and intensity, the single-player experience allows you to compete against friends in Leaderboards or hone your skills with Weekly Challenges. Replay the missions to collect more than 40 in-game Achievements and Medals. For fans who already have a prospering Spartan career aboard the UNSC Infinity, “Halo: Spartan Assault” lets you earn experience points (XP), all-new Achievements, and emblems for your “Halo 4” Spartan, with additional integration features available after launch.

At the time of writing it can not be seen on the UK Windows Phone Marketplace – keep checking throughout the day.