AAAAAAAAAAAAAAND they fucked up. Game misses everything that made the original great.
Weapon upgrade kits? Gone. Replaced with shitty "perks".
Items? Gone. You get 2 starter items now and everything is fucking passive/synergy.
Inventory? Fucking gone. You can only change weapons, but there's no more item strategy. You keep what you get, but it's okay since nothing has a downside anymore.
Special ammo? As far as I can tell, gone.
Soundtrack? Replaced with generic techno and guns sound (and feel) like plastic toys
Crazy gun variants? Gone.
Adrenaline filled combat? Replaced with sparse mobs with terrible placement.
Did you enjoy getting stunlocked occasionally? Now there's even MOAR stunlock
Engineer class? FUCKING. GONE.
Beautiful and unique 2.5D with 200+ FPS? Replaced with generic dogshit-looking 3D that RUNS LIKE SHIT.
Movement slowed to a crawl, guns have much shorter ranges, engagement distances are short and reload takes forever. RIP sniping?
Simple yet functional level design replaced with convoluted 3d crap. At first I thought "nice, verticality" but, HAHAHAHAH, NOPE. You can't shoot enemies above/bellow and I almost ragequit after not finding a shitty teleporter to continue.
Convoluted upgrade trees, terrible UI, chests and shops are hard to make out among the visual clutter
ANIME GURLLLL SHOP => I'm not even joking
I'm sorry, I wanted this game to be good, but it simply isn't and it won't be. The design philosophy behind this "sequel" seems to have been inspired by Diablo 3: remove features, make everything passive, add pointless fluff and butcher the original's "soul" completely.