The alien "Ruins Library" is an action strategy RPG produced and distributed by ProjectMoon. In the game, you will play the role of librarian and lead the secretary to fight the enemy. According to the official website of this game, we can know that the dlc of this game contains aliens, because aliens are the core of the dimension. The basic mechanism of this game is to collect books. Players will send out the first invitation according to the story, and then the relevant players will be attracted to the library by the invitation. The goal of users is to fight them.