The nature of the space is unknown until opened. This space has no gravity or oxygen. You are required to solve the riddle in a short time before you stop breathing. The riddle level is low. There are no Stalkers or other threats here. It is also possible to take the riddle paper and solve it safely outside the door.

The nature of the space is unknown until opened. Upon opening, you are hit by intense heat that feels like it will melt your body. A bridge-like structure spans the area, but it burns away after 5 minutes. You must cross the bridge, solve the riddle, and return quickly. There are no Stalkers, but if you step off the bridge, you will fall into lava. The riddle level is low.

The nature of the door is unknown until opened. This is the ocean, but strangely, you can breathe. There are no Stalkers, but small fish and other sea life are present. If you get hungry, catching fish here is an option. The riddle level is high. Because the area is quite vast, the challenge lies in whether you can find the riddle paper at all.

The nature of the door is unknown until opened. Upon opening, you will be watched by countless eyes on the walls and in the air. Objects float here and may fall suddenly, so you must watch out for falling debris. The riddle level is extremely high difficulty. Stalkers exist in this space. If you are watched by the eyes for a certain amount of time, a siren sounds and a Stalker will come for you. You are safe if you hide inside a wardrobe or similar furniture.

The nature of the door is unknown until opened. This is a beautiful place, much like heaven. It is safe, providing food, a bed, water, and entertainment. The riddle level here is super easy. However, no one knows what happens if you fall. Because no one has ever returned. It might even be nice to settle down here. There are no Stalkers or other threats.

The nature of the door is unknown until opened. A monochrome world where only black and white exist. On a monochrome plain that seems to stretch forever, giant silhouettes loom. The giant silhouettes vanish when approached. The riddle level is normal. Once the riddle is solved, the giant silhouettes all look at you at once. There are no Stalkers or other threats here.

The nature of the door is unknown until opened. Stairs continue upward toward the heavens. There are whales flying through the sky and other fantastical floating objects. There are no Stalkers here. The riddle level is slightly difficult. A crescent moon hangs in the sky. You occasionally fall into a sensation where you don't know if you are real or fake, or if this is a dream or reality.

The door that appears once all riddles are solved. What lies in wait? You feel a gaze upon you when you stand before this door. If you can solve the riddle of this door, you can escape. The riddle difficulty is extremely high.

120cm in total length. A quadruped with low intelligence but high physical ability. It approaches without a sound, and by the time you notice, it's too late. It shares the same weakness as Stalker 2. There are 5 individuals.

An intelligent type that moves slowly but approaches steadily. If you hide in a wardrobe, the Stalker will lose sight of you and vanish. The eyes are its weakness; using a light flash or similar will stop its movement for a certain period. There is only one individual. It leads the Stalker 1 units to perform pincer attacks. 200cm in total length. Communication is impossible.