Demon's Souls is a fun, fantastic and beautiful game... for about a quarter of the time. And really not that difficult.
Let me start from the beginning: I started the game as a Magician, that class is very weak physically and in the beginning of the game its spells are so expensive that they are almost unusable (now when I have played though the game I probably realize that this actually is the "worst" class to start the game with). This made it extremely hard to play the game, almost too hard to be frank. Just to take me to, and beat the fist boss took me about 10 hours (to compare with the 15 minutes it took me the next play through). For a while I though this level of difficulty would hold on for the rest of the game so I almost gave up. But then I changed tactics.
Playing the game in a regular manner and just play and explore and then level up when you got a sufficient amount of souls (which is the experience points in the game) showed up to be a very hard task, mainly because you lose all your souls when you die, but also since my Magician was so weak so I died A LOT and couldn't keep lot souls with regular game play. So I decided to changed tactics. Instead I tried to find places where I could gain souls without dying and then play thous areas over and over again until I got souls enough to level up.
Since the game was so hard I almost became obsessed with this soul grinding for a while. Maybe I did grind a little too much, because all of the sudden the game became almost too easy. Yes, you heard right: too easy! When I reached a certain level I could suddenly run through the levels without any major difficulty at all. And then I noticed that all the levels was pretty short so it took me much less time to finish that I first had expected.
The boss fights was also not much of a challenge. Sure I died a few times per boss but the AI was almost a no-show and as soon as I realized the weak point of a boss it was almost impossible to fail.
It took me about 53 hours to complete the first play through. I estimate that three quarters of this time was just pure grinding. Some players may appreciate grinding, I'm maybe old but I'm no one of them, I just think it is a big waste of time. But since the game was so good for the rest of the time it was almost worth it.
I think the game would have benefit if the difficulty was more balanced, not so hard in the beginning and not so easy if you grind and level up, instead the levels should have been bigger so you can level up by exploring rather than to grind. It could have been top scores, but the grinding part of this game unfortunately lower the score.