I don't know man, I enjoyed travelling through the asylum, while I disliked the open city. It was nice being able to reach new sections with the newly acquired gadgets, and the setting was more appealing to me. And I'd consider respawning enemies in AC a negative thing, especially near the end when [spoilers]there are snipers in the rooftops.[/spoiler]
Upon replaying the game, it becomes clear the progression and upgrade system is exceedingly linear. Not only is the player always told where to go, there's only ever one path to make any meaningful progress in at any one point. All secret areas are just a short distance off the beaten path and only ever contain Riddler trophies or Arkham ciphers. It's a mimicry of a Metroid-like game and the progression is more like F.EA.R. or Uncharted than something like Dark Souls. The level design doesn't hold up to much scrutiny and it's hard to praise it, especially when there's so little to do between fight and predator segments. It sticks so close to the "fight / predator / run through corridors / repeat" formula, with the only breaks being the Scarecrow segments — the hallucinations of which are good, but are followed by the "hide-and-seek" segments which aren't great the third time around — and the Killer Croc segment which is onyl intense the first time, and only if you don't realize crouching cancels out all walking noise.
Also, those
you mention don't respawn. They're only there before the final boss fight. If the player wants to continually beat up more enemies post-game, they can in AC, and if they want to bypass them, it's easy to do so because of the overworld + grapnel boost. That AC has that option puts it above AA.
Most of those gadgets you mention I ended up using only once or twice: during their respective tutorials
They all are useful and well-implemented, even though they all had room for improvement. They each have myriad functions and contextual uses. AA's are comparatively limited, especially when trying to build a combo.
The smoke bomb is useful during fights or predator sequences and stuns/blinds enemies for a decent amount of time, unlike in Origins. REC electricity gun is good for stunning single enemies, knocking back armored enemies or causing gun-wielding enemies to fire uncontrollably and scare/distract nearby enemies. Bat-claw can be upgraded to pull weapons out of hands, can be combo'd into a clothesline (the shockwave of which can stun nearby enemies if done in focus mode), explosive gel is back yet can be used mid fight, gaining a huge blast radius if used during focus mode, and even the bat swarm works for instantaneous AOE stun, even though it should have more uses outside of that.
All of that is optional though, as you said. That they're there to use can't be ignored when assessing the game's quality though. The varied enemies types that all but demand their use in the heat of battle makes it hard to say these gadgets are fluff, or poorly implemented.
You praise the grapnel boost, and while I agree it's fun I don't consider it a good addition, but instead a mandatory one due to the big overworld in that game. I also got really tired of the sneaking parts, and near the end of the game I sighed every time I got to a new one. Maybe it's not the game's fault but mine for having played Asylum before, which felt fresh and original.
Grapnel boost is an option and if people like it, they can use it, if they don't, they can skip it. That said, getting from point-to-point in City really doesn't take much time, even without the boost. It probably takes four minutes to leisurely run + glide from one end to the other of the whole map. Again, it's hard to rationalize calling it a negative when it's optional, allows quick traversal, quick getaways and the grapnel boost ledge takedown. That last one alone justifies its existence and needs to be easier to do in the next game because it's that great.
AA actually has more predator sequences throughout it's main game than AC does, so that's probably a case of fatigue.
Don't get me wrong, I did like the game. I simply enjoyed it less than the previous one, didn't care for the new stuff, and missed the old stuff that was removed. Maybe it's because I rushed the second half due to South Park releasing soon, but the fact that the game eventually bored me still remains.
I would implore you to revisit it with more knowledge of how the game works than you had the first time through. I wasn't sure I liked it as much as AA when I first played it as I was playing it at a friend's house and rushed through it over a few days. Once I got it for myself, I saw the value in all the additions, realized the positives of AA weren't as substantial as I thought and recognized how big a jump AC was from AA to the point that I just couldn't justify going back to AA for any reason.
I don't see how AC 'improved' on anything in AA, the approach was just different (open world).
I always thought City lacked focus. AA only had a few villains and they were given proper attention (Joker, Scarecrow). City on the other hand went overboard and it felt like they were trying to fit too many characters in. I never connected with the story. AA's wasn't the best either, but I was definitely more engaged.
Gameplay-wise, I lfeel like the design of AA was tighter. Initially I thought the open world structure would fit a Batman game like a glove, but the metroidvania-lite approach turned out to be more fun. This is pure personal preference of course, but having Gotham to explore just didn't add all that much, with the obligatory side quests that started to get repetitive fast.
I address most of this in
this post.
In short though, AA's structure was a really lite Metroid-lite to the point it's linear like Uncharted, but with the guise of being intertwining. there's not much about the overworld design (from a gameplay perspective, not an aesthetic one) that makes it that special. The gameplay is still very basic as is the environment and after a single play-through, that becomes painfully clear.
Well there's the batmobile now, so it's likely that they're going for open world more than ever with GK.
Of course I'll still play it, but they're really churning these out a bit too fast. After Origins I would've liked a break in the franchise tbh.
There'll have been two years between each game, and Origins wasn't made by Rocksteady, so there's a 4-year gap between AC and AK. AO was really similar to City without any huge improvements/changes, so it feels like an entire game's worth of "more of the same." As far as quickly churned out sequels, the Arkham series isn't that bad.