To be more detailed, here's my personal breakdown of where Dark Souls 2 succeeds. I feel like the bolded are the more "objective" ones, though obviously that's a loaded term. Mainly I mean the bold are the things I would try and convince someone of while the others I acknowledge as purely taste. For reference my ranking is: DS1 > DS2 == DeS > Bloodborne > DS3.
Positives:
+ inventive, really its own thing as a sequel
+ lore, build a world that had a similar soul but was new, can be played without DS1
+ great zone visual design (Things Betwixt, Majula, Heide's, Wharf, Belfry Luna, Harvest Valley, Iron Keep, Doors of Pharros, Brightstone Cove, Drangleic Castle, Amana, Dragon's Aerie/Shrine, Giant Memories)
+ feels huge
+ some good bosses (Pursuer, Chariot, Looking Glass Knight, Lost Sinner, Najka, Mytha, Velstadt, Darklurker, Twins)
+ DLC is insanely good
+ dual wielding
+ build viability
+ covenants
+ NPC stories
+ weird stuff, like the gender box, the ladle, the old ladies
+ tons of optional content made you never sure if you needed to be where you were or if you discovered something special
+ durability is a real mechanic
Neutral:
+ ADP is a cool RPG mechanic, bad action game mechanic, and I have mixed feelings on it
+ "surrealness" of world (most people here put interconnectivity as a negative but some of us like the weirdness of the connectivity because it really gives DS2 an identity)
+ within zone, pretty well designed for the most part but inferior to DS3 (although for example, does Forest of Fallen Giants really have less to discover and figure out, other than connectivity, than Burg or Walls, proportional to its size?)
+ difference in "speed" of game - DS2 is more tactical and spacing oriented as opposed to the reflex/response of DS3/BB
Negatives:
+ too many mediocre bosses - this was my major complaint from day 1
+ polish level (repeating textures, etc, which I guess make people feel the game is ugly)
+ some bad hit boxes (I never really experienced this outside Smelter's overhead)
+ many of the regular enemies are quite boring
+ no overwhelming high points in base game, like O&S, Gwyn, Gehrman
+ lifegems - like grass, blood vials, and fast estus, makes you sloppy. Only DS1 had good healing mechanics