Well, let's see:
- The dropping of shields and a defense mechanic altogether instead of trying to improve upon it was really hurting the overall experience. While developing BB, FROM somehow thought it a brilliant and modern idea to have players solve every problem in game with rolling and i-frames. Because supposedly it's "visceral" and "flashy" and "encourages you to attack" and "liberates you from fearing a fight". Complete bullshit imho. I know the setting would work badly with shields, but they could have provided some other mechanic (weapon block, etc). So there's no block or bash, and nothing at all to substitute two fundamental mechanics. And this jumpy over-the-top style of play is just not cool at all.
- Covenants are nonexistent. DS2 I believe managed to, for the most part, improve on the half-baked covenant system of DS1 quite well. Now in BB you have 3 "covenants" that require only a single run (read: ring) to equip. There's no covenant levels, no rewards, no lore, no dialogue, no tokens, nothing, apart from some minor bonuses on the rune and 2 covenants of the 3 being mutually exclusive in multiplayer.
- Healing. In BB, you heal by Blood Vials. You can carry 20 initially (runes let you carry 24ish max). Monsters drop them very often and the ones in excess to your 20 vials go into a storage. You can retrieve from the storage in the HUB area (you do so automatically upon death). Healing takes about 1.5 seconds, so almost instant, with vials and restores about 75% health. This makes the game very, very, very easy imho. We're back to Demon's Souls again with the broken 99 healing grass mechanic basically. DS2 did healing very well I believe, the best solution from the series.
- Multiplayer itself also suffered a huge blow. Now don't get me wrong, Soul Memory was a nice idea that got terribly botched in execution, but this BB invasion/coop system seems even worse. You can only get invaded in areas where there's a bell maiden (2 areas in the game), but you can track them down and kill them. If you try to summon, however, no matter what area you are in a bell maiden spawns. This means you will never ever get invaded really, except for when summoning coop friends. This kills coop, because you are constantly invaded if you try to play with friends (and they even provided password-coded games to improve coop), and it kills invasions, because the invader will always be outnumbered and has to resort to hiding behind enemies and other stupid cheesy methods. Add to that the Blood Vial healing, with all players having 20 insta max heals and it's almost impossible to interrupt, so you'll have drawn out, annoying fights that no one thinks is fun.
- No poise. Neither on players, nor enemies. This means everyone can be stunlocked if you have the right stamina. Enemies, who have infinite, can stunlock you to death very simply. And in order to prevent you from R1 mashing through all of them like this, they sometimes get hyperarmor (ie they become immune to stun and attack you during your animations), which is totally unpredictable and causes 90% of deaths. Why not drop health mechanics as well and make it a 1-hit-kill affair? =/
- Items. Very few weapons, armor, and items in general. DS2 may have had too much, but I'd rather have that than have this few. This also unfortunately ends up ruining exploration for the most part, because there's nothing to find anywhere, really. No ranged combat at all, since pistols and guns are only for parrying in close range.
- Magic. It is non-existent in BB. Yes, there are about 6-7 "spells" that are really items you can use again and again with Silver bullets (another 20 max resource). Most take so many bullets you can cast them 1-2 times and neither are useful sadly. The only stat that improves them is Arcane, which is otherwise pretty useless, so few people bother raising it. Caster-builds are therefore obsolete.
- Stats. In DS2 you had about 3 times as many stats, most being useful for one build or the other. Here you have Strength, Dexterity, Stamina, Vitality, Arcane, and Bloodtinge, with the latter two being very obscure and about 10% of players ever level them beyond 10. This sadly means a lot of mechanics disappeared that were tied to stats, and the game is really more Action than Action-RPG.
- New game cycles. They provide nothing at all besides monsters with ridiculous HP and damage output. A complete joke, especially because DS2 improved upon this vastly, with new enemy placement, enemy movesets, boss abilities, and item locations in NG+ and beyond.
- NPCs. When I say NPCs are even shittier than in DS2, you can image how bad it is. None of them are remotely interesting, and none have a longer questline or any depth to them.
These are just off the top of my head. The list goes on and on. Had BB not a remarkable atmosphere and lore with a strong Lovecraftean and body-horror theme, I think I'd really be disappointed in it. It proves to me that FROM kinda lost its touch somewhat.
Also, this is their second game in a row that later they admitted was rushed out to release and had to cut tons of content. Now with BB they are adding it back with an expansion pack. DS2 got the meaty DLC kingdoms. But still tons of basic mechanics got cut. One game had Sony as a publisher, the other had Namco Bandai. This proves to me that there are serious problems in leadership at FROM, either because they agreed to terms that could not be held, or because they could not make the dev team work efficiently enough to finish on time.
Sorry for the wall of text, but I think it could be informative to Soulsborne fans, and maybe show the shape of things to come for DS3. I'm not happy with the announcement entirely, I'd really rather have them make a new, fresh, in a new interesting setting to explore. But Namco will have none of that, they want to cash in on the franchise. So I'm cautious with this one.