A shooter is a sub-genre of action video games the gameplay of which is thoroughly centered around shooting targets. Such games can be presented from first and the third perspectives with the latter being mostly twin-stick platforming shooters. Mouse and keyboard are widely regarded as the best controllers for shooters, as the firing demands high precision achieved only with manual aiming. The primary goal of shooters is to defeat enemies by discharging loads of bullets into them. Shooters are the most discussable video game genre when it comes to judging violence in games, as the gunfire process involves realistic scenes of killing quite often. Sub-genre of shooters is also divided by sub-subgenres such as shoot'em ups, tactical shooters, and hero shooters. The former involves changing a direction of movement and shooting forward while the latter focuses on wiping out tons of enemies by one protagonist. Notable games of the genre are Resogun, Bulletstorm and Call of Duty.