Beat the game. My final thoughts are that it's overall a better game than Demon's Souls, though I feel Demon's had better bosses. My problem with Dark's bosses was that many of them felt simply like oversized regular enemies, with some of them even becoming regular enemies later in the game. Demon's mixed it up with human-type bosses (Penetrator, Allant, Old Monk), environmental bosses (Adjudicator, Astrea, Tower Knight), and gimmick bosses (Dragon God, Storm King). Most of Dark's bosses were simply "you're in a big mostly flat room. there's a fatty over there. beat him up."
Dark Souls's bosses occasionally had their moments. Four Kings had a cool time-sensitive element that encouraged a specific playstyle (tanking) and Ornstein/Smough was an unexpected handicap encounter that was epic all around. Quelaag had a cool area denial aspect but like so many other bosses, it came down to just strafing behind her and beating her senseless. Same with Nito. His whole gimmick is negated with divine weapons so it turns into yet another circle strafe slugfest.
The bosses in Dark Souls were plenty fun to fight, they just didn't feel as varied or memorable as in Demon's. I consider Demon's to have one of, if not the best group of bosses in any game to date so I was pretty disappointed by Dark in this regard.
But enough about bosses. I feel that damn near everything else was greatly improved. The seamless world was brilliant and I felt the difficulty was better paced this time around. Capra was really the only exception to that, feeling out of place in an otherwise-smooth curve. The shortcuts were clever, along with the rest of the level design. Visuals are much improved from Demon's.
I have to talk about the audio. It's meaty. Like, real meaty. When something happens right in front of you, you hear it all around you. Shit booms. I was playing in Sen's Fortress near the boulder area with my room's window open. There was howling wind outside. I honestly had to get up and close my window because the sound of the wind, enemy noises, mechanical sounds, and of course the boulder's audio made the aural experience too oppressive. The audio team for this game deserves a ton of praise.
Great game overall. I still don't think it would have beaten Arkham City for my #1 last year, but it would have definitely been number 2. I'm in new game+ right now, played for about 2 hours and I already beat Stray Demon, Taurus, and the Gargoyles. The game is flying by. I only have the weapons and dark ending trophy to go I believe. Need to beat the game again then beat Sif in NG++ for the final boss soul.
Fun experience.