Demon's Souls was great
and Dark Souls is even better. A very welcome respite from brown worlds full of waist-high walls to "cover" behind and regenerating health.
Difficult is a good thing, sometimes, and boy this game is hard and unforgiving. It's genuinely scary in parts, frustrating in others, beautiful in some, yet the sense of satisfaction when you finally trounce that giant, unspeakably dangerous boss is something I haven't felt since the days of Doom (Demon's Souls notwithstanding.) The feeling from finally ringing the bell in the Upper Gargoyle Church, looking out over the glorious landscape with soft light from the permanently-setting sun above, was a mixture of intense relief at having made it, and immense foreboding at having to fight my way back down again, and then on into The Depths where things were no doubt orders of magnitude more horrific and dangerous. Utterly brilliant. Moments like that are so rare in gaming these days.
The lack of pause button or save/load - the game saves constantly, so you can never use the "save here, try X, reload if it doesn't work" tactic - just adds to the already massive tension.
I'm going to call it - even before I've played Skyrim which I'm looking forward to hugely - Dark Souls is my "Game of the Year 2011"