Thirteen is an interactive 2D puzzle game developed with Unity. The player, who will play as a private investigator investigating a missing couple case in 2008, went to visit the room where the girl of the missing couple used to live before she went missing. Everything in the room seems to be the same as it was 13 years ago: the old-fashioned QQ, Qzone, Qianqian Jingting Music Player on the computer... What is hidden in these outdated applications? Through this computer, you can even interact with the real-world network: how to use today's technology to uncover the dusty secrets of the past? Operating system: Windows, macOS Gameplay Instruction: Use the mouse to click to explore the objects in the game, and use the keyboard to solve individual puzzles.