The Call of Duty mechanics create a positive feedback loop around reward and performance that make the sensation and competition aspects of the game particularly enjoyable. The haptic feedback from hitting a target acts both as reward in that it feels nice, and as encouragement to continue hitting your target until you secure the kill. The leaderboard provides a sense of pride (reward) and motivation to either remain at the top, or to work harder to climb the ranks above your competitors (performance). Killstreak rewards give you an upper hand that lets you get more kills and more rewards in ways that allow you to dominate your competitors. This creates interesting dynamics because maybe you want to camp in a position where your back is to the wall, or at a frequent respawn cite to secure a kill while your target is slightly disoriented. It also heightens the edge of the game because after a certain number of kills before you secure a reward, the stakes feel a lot higher, and you run around praying that you find your next target before someone else finds you. These dynamics create a thrilling, competitive experience.
