Co-op.
It is cool to have possibility to share experience with friends, however it feels like you pay price of better game experience itself.
I played before as a solo for about 15 hours and had a great game experience, learning enemies, attacks; increasing my own skill in game. But playing co-op in 3 or more players - is a full chaos. Game does not feel like it is designed in such way. Arenas are not that big. I cannot imagine playing as 4 players and all in melee builds. Playing with 2handed weapon looks annoying because it is too easy smash a teammate. Same if you will try playing focusing on backstabs. Any attack on enemy will rotate him from required position to backstab.
In general it reminds me co-op in Lords of the Fallen: when you can just spam attacks and enemies will stagger because of poise. Maybe playing on the hardest difficulty is the way, but I think some enemies will oneshot you, which is not pleasant thing. And AI behavior should be re-worked for co-op. You can stay to enemy too close but it will be still focused on your friend.
I would say locking co-op limit up 2 players will be way more better, but I think people will be mad.
And last thing: NPC voice volume for other players feel lower for 20-25% than when you speak with NPC yourself.
Changes in experimental build.
Parry. It feels awful. Like it has some logic: left bumper - block, double tap - parry. However, left trigger becomes completely empty, and double-tap for parry ruins all timings. It is way easier to parry just by left trigger. Possible solutions: 1) Press and hold bumper for block and single tap for parry. 2) Or as it is implemented in many games - using block in right timing counts as parry. 3) Revert as it was.
Torches and runes. We have reached first dark cave and no one have a torch. Looks like it is deleted from granted loot at the start of the game. We were able to clean that cave because I bought rune to ignite my weapon. And there is no way to share these rune with others, because you cannot craft runes and items for sale are not re-stock. It feels kinda meh tbh.
General feedback.
Please do not think that I am hating your game, I am waiting for release of it so much. It is so damn awesome on many aspects, like art design, level design, music and so on. You are making a pretty unique game which is amazing and not a common thing. But I am pointing at things that I would love to see to be re-balanced or re-worked.
Weight limit. Please note that I cannot see game how it will be in general, so I can speak only on thing that I see now. From the start you have 2 armor pieces and if I equip 1 weapon - I can be already in medium weight. Which looks weird, like our character never worn any armor, only clothes and pretty weak. When I am loading my old character - I spend 7 full levels on increasing weight and still cannot equip some armors without going into heavy weight, and I am using a single weapon. Does not feel right to me.
Stats. If I heard correctly - you are going to re-work them. For now, I don’t like how works 4 main stats for weapons. Game requires them only for boosting damage or have ability to equip weapon without penalties. And this feel not awesome. Like in some games increasing Strength will also increase physical damage, Agility - will increase crit chance and so on. Some small bonuses will be awesome addition.
Weapon runes. Some of them are pretty weird. Some weapons requires 100 focus to use them. You see awesome animation, but not that much impact on field. Like rune on mace. It deals damage of 2-3 strikes but applies 0 poise damage, and a lot of these runes can be easily interrupted and you will lose all focus, deal 0 damage and will lose some HP. Too much penalties, no? On other hand rune for 1hand hammer - it ignites weapon and throw it, animation does not required that much time and this costs only 50 focus. It feels pretty ok. I am comparing all to the heal rune 
Fast keys. I really do not understand limitation of keys. Why downward should be potion and upward food? Why I cannot bind food for healing and another food for healing and getting some buff vs tough enemy?