Shooter Fatigue 

verb ~ The act of becoming tired or fatigued while playing an intense FPS/TPS (First Person Shooter/Third Person Shooter) video game.

noun ~ Experiencing fatigue brought on while playing a FPS/TPS (First Person Shooter/Third Person Shooter) video game.

When I killed the whole other team myself in Gears of War I noticed I had Shooter Fatigue.

Shooter Fatigue by Stoppable July 18, 2009