I have put a bunch more hours into the game, since I went in blind. More feedback:
I quite literally mean player versus environment, not the monsters. It's often frustrating.
First up is movement. The constant clicking required to go from one place to another gets really old, really fast. It doesn't help it's buggy and clicking certain places on the screen makes the character stop instead of going towards that location. Sometimes it means death, if trying to run away from a monster.
Fixing the buggyness is what the testing is for obviously, but I don't think that is enough. I think the game needs a toggle for autorun. You still click to change direction when the toggle is on, but you keep going forward no matter what, until you toggle it off.
Next we have the trees and other objects that affect targeting. Navigating and fighting in dense forest is also frustrating. Not challenging in a good way, as games can be, just frustrating.
The game needs some click-through mechanics and target priority settings. For example, stuff obscured behind trees for the player, but that the character can see, needs to be visually outlined somehow, and easily clickable. Plants, rocks, monsters, dead lootable monsters.
Monsters should always be the top layer in terms of clicking, with a generous click-hitbox. It's not just trees, it can be the dead lootable monsters the attacking enemy is standing on, or even the fire totem the mages cast, that interfere with actually targeting and attacking the monster. It's not always possible to run into open, flat clearings to fight.
I really like the progression concept of the game, with creature knowledge and skills being opened up, the more you kill a monster. I think that is a great concept. I understand there will be more worlds, and that you won't be able to just freely travel to them and easily learn everything there as well.
However, I see a problem with how you have to spend the same resource on both unlocking skills and putting points into the talent tree. At any given point, there is a finite amount of knowledge points in the game. This means that if you spend KP on unlocking a skill you end up not using anyway, you have essentially gimped yourself compared to someone who hasn't done that, and instead put those points into the talent tree for bonuses. This is a fun-killer, if you can't recoup those misspent points.
Hopefully the game won't have so many KP that the system becomes moot anyway, where everyone runs around with 100% of skills unlocked, and 100% of the talent tree filled.
So I suggest going with either of two systems.
Let players lock skills again and regain the KP. This can be a moneysink, if need be, but preferably not too expensive. You want players to experiment with skills.
Remove the KP cost for unlocking skills altogether. This will require some rebalancing of the entire knowledge point system, yes, but might end up being the better solution long term.
Players will still be limited by Memory and the need to rest at a fireplace to change skills, so it shouldn't affect PvE or PvP combat balancing at all.
Overall, I like this game. It's addictive in many ways. It has potential to be a lot of fun if the frustrating parts are fixed.