I dont have a PS3, so how difficult was the original ? Compare it to any other games ?
Also is cobat real time or stat based ?
As others have said the learning curve is steep. You will be punished for your mistakes. But as you may have heard the game does not give out cheap deaths, but there is ALOT of trail of error. In this way it is very much like a 2-d scroller, you have to learn the game's patterns before being able to complete a level or beat an enemy.
Also the game's souls system is quite unique. You are rewarded souls for killing enemies. You either have to spend the souls on leveling or gear or carry them with you. If you die, your souls are left at that spot in the level and you return to the begining of the level. You then must get back to that point in the level to retrieve your souls. If you die again before retriving couls, bye bye souls.
It probably took me 5 hours to figure the first level. Kinda embarassing, but that should give you an idea of the learning curve and I never looked stuff up on the internet. Now i can beat the stage in 10 minutes. Go figure.
Combat is modifed by stats. Weapons have pre reqs like STR, DEX, MAGIC. You basically invest in damage, endurance, health. It is still very much an action rpg that depends on player skill, but the character building is so VERY deep, deeper than some other non-action RPGs.
It is interesting that many people compare this to the older NES ninja gaiden series. I always thought this before reading it here.
No world tendency this time? Aww. The reasons are understandable, but I rather liked the whole idea of the game's difficulty changing subtly in the background. I'm also slightly disappointed that it takes place in a whole new world. I rather liked (what little) we could see of Demon's Souls world and would have liked to have seen it expanded.

That aside...[censored] YES! Look out, Skyrim, you might have a serious contender for Xet's best of 2011.
I was disappointed in this as well. The character tendency and world tendency were very innovative additions to the game. And I was astonished to find the game got HARDER the more I died. It also had some impact on the multiplayer component altering DAM and HP depending on world + character tendency. I hope if is going to be replaced by some other tendency system. It took me SO long to properly manipulate the world/character system properly.
And I just bought Demon's Soul too.
Let me known if you want any help

. My PSN is Ratt_707. I just started a new game, again.