As a FPS player I also learned from many friends and went to understand the game.

The game has a 5v5 team versus team mode as well as a co-op mode that can be challenged by 1~5 people
The co-op mode doesn't necessarily have to eliminate all enemies but can also capture them in specific scenarios. The game has complex AI enemy mechanics each game will randomly plan patrol routes and will also interact with the environment (such as hiding under beds cabinets) and will also take hostages as meat shields giving the player a high level of challenge. Under certain circumstances individual enemies will also surrender.