Video games are often known for their gun play. However, not all shooting games are the same. The simple aiming and firing mechanic is creatively combined with other aspects of play that greatly alters the experience.
Movement Shooters are shooting games where you have a high degree of control of how your character moves around the world. Along with the usual walking, running, crouching, there are ways to swing, jetpack, climb, wall-run and generally use parkour-style motion to get where you need to be.
This not only adds novelty to the otherwise repetitive nature of shooting games, but changes how they are played more generally. In a standard shooting game, a viable tactic is to hide somewhere and pick off enemies as they appear in the distance. Movement Shooters get around this unpopular technique (sometimes called "camping") because the ability to rapidly move through the world enables you to find and deal with hiding snipers.
The movement aspect of play also adds another significant skill to learn in these games. Techniques like Strafe-jumping, Circle Jumping and Bunny Hopping enable players to squeeze fast motion from their character. Add to this the combination of swinging, gliding and using architecture to transition smoothly from floor to sky and its clear that this can take many years to perfect.