Games often have a story plot that runs through from beginning to end, and each level is under this story framework. The role played by the player needs to complete specific tasks in different scenes. For example, in the abandoned factory level, the player needs to first eliminate the enemies hidden in various corners and then find and dismantle the bomb. In the mysterious castle level, the player may need to rescue the imprisoned hostages and successfully break through the enemy's heavy defenses. As the levels progress, the plot will gradually unfold and the difficulty will also increase accordingly. The number and types of enemies as well as their attack capabilities will become stronger. At the same time, more complex terrains and mechanisms may appear in the scene.