Esports (also known as competitive gaming), earned their fair share of the game industry over the last decade. Nowadays, esports account for a large portion of gamers, viewers, and organizations. Among games played as esports, first person shooter (FPS) games are arguably among the most popular. This includes well-known titles like Quake III Arena, Counter-Strike: Global Offensive(CSGO), Overwatch, PlayerUnknownÕs Battlegrounds (PUBG). While these games seem to share similar game mechanics, what constitutes a popular and successful FPS game in esports is both (1) evolving rapidly and (2) have not been systematically reviewed prior. I qualitatively and quantitatively explore game mechanics of FPS games in esports and how they have evolved in time. This results in a taxonomy that can be used to identify specific game mechanics for different FPS, as well as explain how these mechanics evolve over time. I conclude by discussing how the model can be used by game designers to inform the design of FPS games and help inform future trends in game design for esports.