Halo: Spartan Assault is a sci-fi top-down shooter developed by 343 Industries (in conjunction with Vanguard) and published by Microsoft for the PC (via Windows Store) and Windows Phone 8 devices on July 18, 2013. It is a spinoff title of the Halo franchise, in similar vein to the top-down real-time strategy title Halo Wars. It was later released for the Xbox One (as a digital title) on December 24, 2013, and is planned for the Xbox 360 sometime in 2014.
Set between the events of Halo 3 and Halo 4 (where the Human-Covenant War has ended and the SPARTAN-IV Program is in its infancy), players play as one of two SPARTAN-IV soldiers (Commander Sarah Palmer and Spartan Edward Davis) as they defend the colonies of Draetheus V (and its moon, X50) from a Covenant splinter group.
Like traditional Halo games, players can drive vehicles, deploy grenades, use melee attacks, and switch between a variety of human and covenant weaponry from the battlefield. Players can also turn on various "skulls" to handicap themselves (in unique ways) while increasing the amount of score and experience points earned in the mission. The game also supports paid microtransactions (for quick boosts, special abilities, and unique weaponry), leaderboards, cross-platform game saving, and integration with Halo 4 (allowing players to earn experience points and unique content for their respective Spartan Career).
Halo: Spartan Assault supports a variety of control schemes, including touchscreen support (for the PC and Windows Phone versions, adding a set of virtual "thumbsticks" and "buttons"), gamepad support (for the PC version, after an update, and all console versions), and mouse/keyboard support (for the PC version only).
On August 29, 2013, the game received a free update, titled "Operation: Hydra", which added five new missions, five new achievements, and a set of updates (including official Xbox 360 gamepad support for the PC version and support for low-memory devices for the Windows Phone 8 version). The Xbox 360 and Xbox One versions add a new online co-operative campaign (for two players) where players must fight the Flood.