If you can finish Demon's Souls in under an hour, you are not human. Someone did, anyways.
A Japanese man, known as alternalw, apparently finished the From Software RPG in 54 minutes and 54 seconds,
Demon's Souls is known to be a proper bastard in terms of difficulty.
The game released this summer on PS3 from Namco Bandai, following much demand following its previous US release from Atlus and Japanese publication by Sony.