Well.
Unfortunately game is much more weaker than DkS1. And this includes design of the bosses, design of the level, mobs actions and their locations. No death punishments, for example Balder Knight with Rapier will kill you by riposte, Hollow soldier with Estoc will parry you but will not finish you off.
Map design. Too linear, in some places you can see another locations. Like a corridor in the sky when you arrive to Bastille from No man's warf. So places like Iron Keep too complex, they do not add challenge to the area, but instead they add frustration. Sen's Fortress is fun, Anor Londo is fun - Iron Keep is boring. You can have 60 poison arrows in your first playthrough and these arrows will make Iron Keep run a cake walk. So why all that mess there in the first place?
Bosses are so easy and this is so sad. I begin this game in Covenant of Champions and made it to NG++ in this Covenant without any problems at all. As a matter of fact - fighting bosses alone is much more easier than fight them with NPC or another player or players, because you can predict the behavior of any boss easier. The only two fight i can actually name as more or less challenging: Double Pursuers - which you can fight one at the time if you want to, and DarkLurker which is ok but... yeah too simple even on NG+5.
Smelter Demon - this boss is harmless, Freja? Harmless. Rotten? Harmless. Sinner.. well in NG+ she is kinda tricky because of two red phantoms, but.. yeah. Ancient Dragon - worst design ever, this boss is pathetically easy, but if you are slow for any reason - he will one shot you. As i said - bad design.
Mobs can track your movement or your aim, but most of the time it won't help them, because you can make a lot of mistakes and game will forgive you.
Hit boxes of certain bosses are very badly made. Last Giant and Ancient Dragon are examples of this.
Arsenal. In DkS1 you could do well in both pvp and pve with any kind of weapon in your disposal, short sword could be just as deadly as a halberd of the black knight. In DkS2 only few weapons are viable, unless you are some kind of enthusiast.
Souls Memory. Yeah...
Covenants. Well SunBros are ok, because you can't actually somehow ruin it. The other covenants... Well some of them add some additional content. Covenant of Champions is rather sad, because it brings nothing new to the game, Bells, Rats, Blue and Reds... well first two are pvp-wanna-be covenants. Arenas for Blue and Red is a bad decision in general.
Pvp. With some many things broken in the game - like speed of estus, poise and dark magic, with the same crappy net code? well it's actually a shameful display. Although after SM 16m, i had some decent pvp as invader and as target for invasions. Honourable duels, almost just as good as in DkS1.
Lore. Well Lore aspect of the game is immense. If you are in for DkS lore - this game brings a lot of thing to think about. Lore is made very well indeed.
Grind, be it materials for upgrades or sets of armor - you must grind a lot. For example for Auros Set i killed 20 phantoms and as result 20 bosses of that area. Sad.
In general DkS2 is a good game, best game of this year so far. Well it's made for broader audience and this actually made game worse. It's too user friendly, too forgiving. Backtracking in some cases is too short. Ability to clean the area of mobs actually did more ill than good. Bosses are too easy, environment and mobs too simple.
p.s. and controls for pc version is horrible.
p.p.s. if you are a veteran of Souls games - you already know all the flaws of DkS2... shame really.