Halo Wars is a real-time strategy game set in the universe of Microsoft's blockbuster first-person shooter series. The game was created specifically for Xbox 360 by Ensemble Studios, the developer behind the acclaimed Age of Empires and Age of Mythology series. The focus of the game is on combat and conquest, with resource management taking a backseat to battlefield tactics. Units, vehicles, and the supplies needed to keep them running are produced at different buildings on base. In most missions, players order down the buildings they need on the planet's surface in pods sent from an orbiting command ship. The game's control scheme revolves around large, contextual, circular menus, designed with the Xbox gamepad in mind. The D-pad can be used to jump quickly between important spots on the map and the face buttons are used to select units and give common commands.
The main Halo Wars campaign plays through a series of scripted missions that follow a storyline set 20 years before the original Halo: Combat Evolved. Players control United Nations Space Command forces in a command ship called Spirit of Fire, on a mission over a distant planet called Harvest. The alien Covenant had taken Harvest from the UNSC and the UNSC has just taken it back, but Covenant activity continues in remote locations. When it is discovered that this activity centers on ancient Forerunner relics, hidden just beneath the surface and undiscovered during the humans' previous occupation, war on planet Harvest becomes a lot more interesting.
The looks and sounds of the vehicles and units were designed to match those of the original Halo games in detail, with zippy warthogs, wise-cracking infantry, and raspy, zealous aliens. A few units are introduced in this game, along with new hero characters, who fought the Covenant in the days before there was a Master Chief. In addition to the single-player campaign, a multiplayer mode is available for as many as six. In multiplayer games, players can choose to take command of the Covenant as well as the UNSC. The sides have different strengths, but each has unique powers that can turn the tide in a fight if used wisely. Capturing Forerunner relics on a map yields advantages, as well. During the development of the game, Microsoft announced that it would close Ensemble upon completion, making Halo Wars the swan song to the studio's successful, 14-year run.