They've done it again...
I'll keep this brief - Dark Souls is improved in every way from Demon's Souls.
The graphics are gorgeous, just stunning. The animations are pinpoint...when a giant boar is stampeding toward me, I can almost feel the earth rumbling beneath me. When the sword from a dark knight just misses my body, I can almost taste the dust that explodes from the ground and blinds me for a brief moment. When I climb a tall building and look outside, I feel a sense of calm as I look at the sun and sky.
Hand in hand with the graphics, the controls and gameplay are so precise (exactly like Demon's Souls). If I make a mistake, it's because I made it, not because of the game mechanics. The biggest difference I have found from Demon's Souls is they've slightly made it more difficult to parry an attack (which is a nice improvement as it was too easy in Demon's Souls). The environment is your best friend and your worst enemy. Every cliff, ledge, pillar, tombstone, stagmite, and anything else can be used to your advantage to evade death or push your enemy to their demise and vice versa. The enemies are smart as hell....they team up on you , they force you into corners, they change direction of their attacks at the last second if you dodge too early, and they will riposte you if you are careless with your attacks! It requires constant attention to take down even the simplest of enemies if they are grouped.
I can go on and on about this game, but if you're considering getting it, I highly recommend it. You will feel such a sense of accomplishment when you master it's mechanics, and the sense of excitement and fear it brings you as you traverse it's world and unravel it's secrets is matched only by it's predecessor.