Lost † Game is a Japanese Yume Nikki fangame. Unlike most Yume Nikki fangames, the main character, Sakura, is already dreaming. She seems to be trapped in a dream world full of strange creatures. The chasers, known as reapers or "death gods", can harm Sakura directly.

Outside of minimal dialogue, Lost † Game is unique in its use of a Game Over system upon being captured by a chaser or otherwise trapped. To compensate for this, the player can save at any time from the menu. To reach the ending, all thirteen Symbols must be collected and placed in the coffins seen at the start of the game.