Gun is a Revisionist Western-themed video game developed by Neversoft. It was published by Activision for the Xbox, Xbox 360, GameCube, Microsoft Windows and PlayStation 2. The game was released in North America on November 8, 2005, and in mid to late November in Europe. Since October 13, 2006, the game has also been available to buy on Valve's content delivery platform, Steam. It was released for the PlayStation Portable under the title Gun: Showdown on October 10, 2006. It features new side-missions, a multiplayer mode, and other additions that weren't available in the console versions.
In its first month, the game sold 225,000 units across the four systems it was initially released for. According to TRST sales data, the game has sold over 1.4 million units in the US (as of October 2008). It was well received by professional game reviewers and Activision noted that Gun sold the best among new video game properties. The game won Gamespy's "Xbox 360 Action Game Of The Year" award.