I am developing “DOOR” by myself. Before becoming a game developer, I wanted to be a writer, so I want to the tell the story of this game in my own words and in my own way. From concept design to prototype creation, it's been 2 to 3 years. While trying to find the most effective way to express the game essence, several versions were made along the way. Now we have reached the final version. The concept of DOOR is based on the idea that "the handle that opens the door of the heart is inside." Since the game’s setting is the mind, we wanted to focus on expressing it. As a developer, I call "DOOR" an "art platformer" game because the world of the mind is represented in various ways. The gameplay is a Mario-like platformer where the player overcomes puzzles and obstacles.