Halo Wars received generally positive reviews. Ensemble was closed by Microsoft before the game's release, but soon after Robot Entertainment was founded by many of Ensemble's former employees this new company continued to support Halo Wars with updates and downloadable content. Ensemble designed the game specifically for the Xbox 360 controller, in an attempt to circumvent issues present in previous console RTS'. Halo Wars was unveiled at the X06 Xbox show in 2006. The player leads human soldiers aboard the warship Spirit of Fire in an effort to stop an ancient fleet of ships from falling into the hands of the genocidal alien Covenant. The game is set in the science fiction universe of the Halo series in the year 2531, 21 years before the events of Halo: Combat Evolved.

It was released in Australia on Februin Europe on February 27 and in North America on March 3. Halo Wars is a real-time strategy (RTS) video game developed by Ensemble Studios and published by Microsoft Game Studios for the Xbox 360 video game console.