Undertale is about a child who falls into an underworld filled with monsters.
Undertale the locked door in.
Repeat a few times to get a key to his room.
The mysterious door is an area found in snowdin forest south of the right side of the room with the icy x s and o s puzzle.
Save before talking to sans at the end then reload.
The door which bears the delta rune is surrounded by glowing mushrooms and floating particles.
If you are defeated by papyrus instead of seeing a game over screen papyrus will capture you and lock you in the guest room.
That key will open the back door.
It s not actually locked though and the bars are too wide to stop you from leaving.
By the way there s two other keys that you might want to check out if you already haven t.
We re an unofficial community of fans and a showcase for undertale fanwork.
After that you go into sans room and will find another key on a box.
In the nintendo switch version examining the door leading to mad mew mew in the dog shrine before it is unlocked yields a message saying that the door is locked by a mysterious seal as an ominous piano jingle is heard.
Undertale by indie developer toby fox is a video game for pc ps4 vita and switch.
Then snoop around there to find an another key that unlocks a hidden door behind the house.
First you have to get the key to sans room.
Don t worry though he gives you a nice bed and some food.
Finally i got around to doing this.
To do that you have to save just before he judges you and then reload several times until he gives you the key.
Glyde can be encountered in this room before fighting papyrus.
To open this door you must dodge every name during the special thanks portion of the credits after a pacifist run.
Come join the fun.