According to Dexerto, the Gun Game option in Call of Duty: Modern Warfare 2 has the old mini-map, which allows fans to see red dots anytime an adversary shoots a weapon. This has been a contentious issue in Modern Warfare 2, as some fans want this mini-map to return to Call of Duty games, while Infinity Ward claims that it does not want to penalise players for shooting their guns.
Gun Game differs from a standard 6v6 Call of Duty: Modern Warfare 2 battle, which might explain why it has the familiar mini-map. In a Gun Game battle, users are charged with killing adversaries with a sequence of firearms in the shortest time possible, with the goal of becoming the fastest player to cycle through all available weapons.