Saying that Darksiders 2 is a balance act wouldn't be false, it tries to be so much at the same time, improving in some ways over tried and true staples of the genre but lacking in other parts of it's systems. I haven't played Darksiders 1 but I assume that the sequel is higly iterrative with some ideas from the original. A side effect of me not having played the first one lies within the fact that I was surprised how Zelda-esque it was (A realisation that most people who played DS1 knew all about by then) and how it added so little over the classic formula.
This game is so much like Zelda, N64 Zelda even
I'm really surprised how derivative some elements are. You could be making a checklist of everything that zelda and DS2 have in common and it would be quite long. It's not a bad thing by itself but as I was playing it, I tried to figure out how I liked it, was it old-school gameplay in a modern packaging or where they only reusing core concepts and leaving more modern ideas inside the control and feel of the game. You need to find keys to open locked doors or activate switches (even with the a little jingle), you have the equivalent of a bow and arrows, bomb flowers are there as-is, you collect tome pages instead of skultulas, each dungeon or so you find a new piece of equipment that lets you explore different parts of the world and there is also a great tree (of life).
Setting-wise, this is nothing like Zelda but in many other ways, it's painfully similar. For people that never played the Zelda games, this might be something new and interesting and there might be some enjoyment out of the nostalgia, but I can't help but feel this is a cheap way out. There's even a navi-alike in the form of a raven that points where you should go next.
How I would fix this
Change some items and systems in place so they behave a little bit differently, bomb flowers for instance didn't need to be literally bombs growing in specific spots that regrow after you threw them. At least they made the bow and arrow a gun. Also they made "statue" puzzles be rolling rocks instead, makes it more easy to move them around.
Some improvements are made.
Of course, I'm not saying that DS2 is only a cheap Zelda knockoff, many things that bothered me in Ocarina of Time are fixed here like the horse being instantly summonable and dismissible, there's more traversal stuff and it feels more natural than the clunky movement of Zelda games, you can easily parkour around the environment to find hidden things and proceed to the next areas, combat is much more interesting and there are more options with skill trees and loot systems. You gain quests to add more content to the game, you can fast travel really easily between maps and various other system are improved.
As a action adventure game, DS2 would be perfect - even tho maybe a little thin in content - because it does most of the same thing as old games of that genre, but it does them better. The setting is interesting, the characters are too, the gameplay feels good and the puzzles are fairly challenging at times.
But then it tries to be another game
Most of the RPG elements in Darksiders 2 should go away or be modified enough to make the game flow better. An annoying thing in the Zeldas of time past was to go into your inventory to equip/unequip certain items (Such as the iron boots in the water temple), it stays true here that it's annoying to keep going to the same subscreen to compare items you just picked up with ones you have equipped. The fact that they give a lot of items as DLC also ruins the game in some capacity because it trivializes battle content.
Fixing this first thing
Why not just display the stats while you're picking up the item? Also letting you loot + equip at the same time, that would help a lot. Also, giving better items is fine as DLC as long as it doesn't make the game as easy as regeneration did in DS2. No need for potions anymore when you get to full life just standing around.
The skill tree is interesting even tho I wished the skills lasted longer, I took the summoning/spells tree and having to recast my ghouls every six seconds is kind of annoying, especially playing on the PC. That reminds of of another problem this game has, there are so many buttons mapped to individual specific things. All the number keys are used for something and most of the right side of my keyboard also.
Fixing this second thing
You simply need to add wheels or quickslots or something. You move between your spells using a key, you cast your selected spells using another, no need to hit the 7 key too summon ghouls or the 6 key for a magical shield, you just select it then cast it. Mapping things to the middle mouse button is not the most elegant solution for the gun, especially because it's quite a fun weapon to use.
Darksiders 2 didn't need to be an action RPG with tons and tons of different inventory slots and stats and skill trees, it would've been a neat zelda clone instead (Probably like Darksiders 1 was). I understand that it's not possible to make AAA 'zelda clones' and that people always want more, but in DS2's case, what they added upon the formula didn't do much good.