Stockholm is the 30th floor, where the player can explore in a small, pitch black room with only a bench and a seemingly depressed man sitting on it.
The man sitting on the bench is Simon Henriksson - a main protagonist in a indie survival horror game, Cry of Fear. The floor is a direct reference to the Beta Simon easter egg in Cry of Fear, where you can see for yourself by entering the TL Trading AB building and interacting one of the doors with a package you can get by finishing the fourth ending.