This is a 3D single-player cooperative decryption game. 1. Game background: In the spring of 2015, the protagonist Lili's parents died in a car accident. Lili, who lost her support, spent a long year alone in the big empty house. Sadness and loneliness left a huge psychological shadow on the young Lili. She especially hopes to be accompanied by someone, even if that person is herself... So in her dream, she went back to the past. The movement of the mechanism in the game represents a memory when she was with her parents. When triggered, a past dialogue will sound. . While rationalizing the movement of objects, a plot is shown, and after the knot is untied, the calendar time changes back to 16 years, implying a return to reality. 2. How to play: The player controls two characters successively, and the character controlled by the player will record all actions. After the player switches to another character, time returns to the beginning, and the previously controlled character acts according to the recorded actions. Therefore, the player will cooperate with the previous self to pass through many organs together. Use WASD or arrow keys to move (the virtual joystick is temporarily unavailable), drag the mouse to rotate the perspective, the space bar to jump, and the Enter key to switch roles.