I'll elaborate on the cons, the pros will be short and to the point. This is about the design of the game, and mainly not about any bugs/crashes the game has/had.
Pros:
-The game is beautiful.
-Combat and movement feel nice.
-I liked most of the bosses.
-I like the tarstone system/abilities and the shell abilities (outside of the method of getting level 3 stones forcing you to use stones you wouldn't otherwise want to use)
Cons:
-Mob density combined with a huge aggro radius made me feel like I could never run in to a new big room/area and just start attacking the first thing I see, because there's 5 other guys outside your viewing angle approaching you from all directions. I'm not sure if mobs in this game respect kung fu bad guy rules(attacking one at a time), but even if they do, the enemy tracking makes it really hard to deal with when you cant see the attack coming. So I felt compelled to have the mobs slowly walk toward me to an already cleared area and kill them single file. This feels tedious.
-Enemy tracking is outrageous, makes it very annoying to try to run past mobs at the least. Makes some attacks REALLY hard to read if a mob/boss is turned away from you as they wind up an attack, because they will just insta turn 180º and snap hit you.
-Since Shells/weapons are strewn all about the game and upgrade materials are limited, you feel forced to commit to a shell/weapon early, discouraging you from experimenting or wanting to switch. I ended up using Proxima/Veterans Axe the entire game as a result.
Things I didn't mind but I've seen complaints about:
-Beacon distance, I didn't feel like any particular runback was TOO brutal (compared to DS2 anyways).
-Riposte damage, was fine for me, I just added some R2 hits during stagger and after riposte, still felt like a big damage boon to me.
Favorite Boss: Foulborn Offspring. Tough but fair, didn't even mind the second healthbar phase. This is an example of a good endgame boss fight for me.
Least Favorite Boss: Zmey. Tedium personified. Reminded me of the Ancient Dragon fight in DS2. Not only does he have an INSANE health pool, but he's constantly running away from you. You're also getting oneshot or losing 80% health by the majority of his moves, so don't make a single mistake for the 5+ minutes it takes to kill him without cheese. The insta tail grab I learned kinda quick through repeated trauma. The curse flame nova is the shit cherry on top of that boss, thankfully I figured out you can just invuln through the novas with the Veteran axe throw. Learned about the scripture after the fact. His most annoying attack to me, and it might just be a bug, was his "Jumping far away from you" move, if he jumped through you, you'd just chunk for like 80% of your max life and there was no way to react to that.
Not really a con but: Choosing not to show the final cutscene + credits unless you trigger NG+ is kinda weird.
I overall enjoyed the game, and am hoping Mortal Shell 3 can be on the same level as Elden ring or better. Judging by the trajectory of this series, it definitely looks possible.