Demon’s Souls director Hidetaka Miyazaki has told Game Informer that the game’s difficulty was designed so that players would feel “a sense of accomplishment” regarding the collection of souls.
“If the Souls could be recovered anytime, there would be no suspense or sense of accomplishment,” he said. “[We want players to feel] like, ‘I can’t die until I get all those souls back,’ or ‘I did it! I made it to my bloodstain!'”
For those of you who have yet to play it, souls gained through fallen enemies are lost once you die. You only regain them if you make it back to your “bloodstain” on the ground without dying on the way – because there can only be one bloodstain at a time.
Mind you, you have to fight everything again, so if you do make it back you the souls you had when you met your demise for the 800th time will be there waiting, which means double the souls in a sense.
The game is difficult, no doubt about it. Currently, the game is being played in the next room and we hear very loud obscenities coming from it as we type.