Demon Souls
+ Boletarian and Latrian levels (and their bosses) are very iconic and intricately designed.
+ Movement options and attacks are very responsive and stamina regenerates rapidly.
+ Leveling up, upgrading, infusing, and collecting feels rewarding.
- Many weapons perform poorly (recoil against environment and barely chip enemy's high armor and poise).
- Swamp of Sorrow and Ritual Path are a chore.
- Obtuse design choices like World Tendency locked areas/events, default 50% health, and upgrade system.
Dark Souls Remastered
+ Refined movement, addition of kick/other offering riposte opportunity against blocking, addition of jump attacks and more unique weapons.
+ Areas around Firelink Shrine are interconnected in interesting ways.
+ Very iconic NPC characters and bosses.
- Delay between inputs, movement, and attacking.
- Whips, fist weapons, crystal infusions, and raw infusions are bad.
- Bonfire warping, orange fog gates, many infusions, and boss weapons locked until late game.
Dark Souls II: Scholar of the First Sin
+ Soul vessels (change stats), bonfire ascetics (NG+ an area), incenses (lower magic requirements), dual wielding, and streamlined infusions/upgrades/trades.
+ Many areas immediately explorable, fast paths to desirable collectibles, and rings for specialized builds (like Gower's Ring of Protection for glass jaws).
+ All expanded weapon classes, magic classes, and upgrade paths are more balanced and better complement faster movement.
- Slow stamina regen, item use, and recovery animation after limited heavy attack combinations.
- Item use speed and invincibility frames of rolls and backsteps tied to adaptability stat.
- Without Bracing Knuckle Ring durability for many weapons is shockingly low and kick replacement is generic.
Dark Souls III Deluxe Edition
+ Movement is less stamina demanding and fully complements attack options which now include weapon arts and charge attacks.
+ Infusions now allow changing the strength and dexterity scaling of weapons.
+ Really neat implementations of ideas like mirror versions of Untended Graves/Firelink Shrine areas and summoning the undead Nameless King to Dragon Peak.
- Leveling up, upgrades, and infusions feel like being nickel and dimed while progression is extremely linear.
- Terrible boss battles with one hit kills that only allow chip damage during tiny windows of opportunity and absurd phases like resurrection/fusion.
- Poise limited only to heavy attacks of certain weapons and slower kicks really limits usefulness against rabid enemies.
Bloodborne Complete Edition
+ Dashing, blood vial injection, expanded weapon attacks (including amazing charge atttacks), easy gun parry, and rally (counter attack healing) are fast.
+ Chalice dungeon glyph materials/weapons/blood echoes, blood gem stacking, and caryll rune stacking make a little grinding go a long way.
+ Enemies including bosses now recoil and get stunned from player attacks giving a sense of power and believability.
+ The world's iconic story and structure are fully interconnected and its progressive descent into further chaos is witnessed firsthand.
- There are few weapon options and very little magic to choose from (but fortunately they are mostly good).
- The game doesn't require chalice dungeons but practically everything great is relegated to them and they are very repetitive.
- The game is very linear and a lot of the best collectibles are only accessible past mid game while forcibly having to pass through Hunter's Dream between every lantern warp.
Opinion
I have to give the nod to Dark Souls II: Scholar of the First Sin for its redefining of what is possible within a game of this action role playing game subgenre for replay value but the gameplay innovations in Bloodborne make it a close runner up. If Bloodborne dropped the chalice dungeons and made an effort to give easier access to goods in the main game I would have given it the edge. With that said, I have no opinion on Sekiro or Elden Ring as their settings are of no interest to me and their issues are far too glaring for me to give them a fair shake.