Not really all *that* dark but I put my Sims 3 family in a house with no corners,every single wall had mirrors and there were no windows. The son spent his entire time in his room until school age,his only companion being his imaginary friend. His parents went nutso with the mother spending her entire existence writing,writing,writing and the father working to create a potion to bring the imaginary friend to life before he succumbed to the madness. All the while I would have university students move in as housemates and would lock them in a room and kill them. The graves piled high. Eventually the mother was turned to gold through the Philosopher's Stone and the son would wonder who the statue in the garden was modeled after.