Games usually construct a science fiction space story background, and each level is embedded in this plot. The role players play may be a space warrior, shouldering missions such as defending the universe base, exploring mysterious galaxies, or combating alien invasions. For example, in a certain level, players need to break through the enemy's defense line set up in outer space first, and then enter the interior of the enemy's space station and destroy key facilities to prevent their evil plans. As the levels progress, the plot gradually unfolds, and players will encounter more types of alien enemies. They have different attack methods and weaknesses. At the same time, the scenes in the levels will become more and more complex, such as interstellar passages full of traps and areas with powerful energy shields.