A lot of discussion about D4 gameplay is centered around ideas like “meaningful combat”, engaging combat, and various encounters being too easy or difficult.
I believe there are two overarching groups of game factors that feed into difficulty and challenge.
First is the numerical aspect, or simply put damage vs enemies’ health and their damage vs players’ health. I won’t be talking about that.
Second are the mechanics. That meaning in game functions the players can do with controls: moving, attacking, activating skills, dodging, etc.
What I would like to see evolve in Diablo 4 is more mechanics that both the enemies and the players can utilize. This is the only way I see difficulty being anything more than a numbers game concerning enemy volume and magnitude.
As things stand, a seemingly large group of players would like more engaging combat, me included. However i do realize given the limited mechanics of move, dodge, and attack there is really only so much an arpg can do. I mean what more can really be done? Add quick attacks that the player needs to dodge or move themselves away from, zoning, and attack/deal damage. I have played other arpg’s and this is always the limitation before I realize I should be playing another game type if I want more detailed combat.
There is room for improvement though. If Diablo 4 were to overhaul, add, and invent new and existing class features and skills for both players and enemies. Features such as activated abilities in the form of skills like deflecting, blocking, grabbing, or whatever else can be conceived of. The counterplay of having to combat enemies that can do these same moves along with unique moves that would be inherent to hellish enemies would be a massive improvement to the gameplay. I would leave the question as to which specific mechanics should be added as an open ended one, as there is much to consider, and that would entirely be a developer issue.
This clearly would be a considerable amount of work, but still in the realm of possibility. That is my plain conceptual suggestion primarily as Blizzard feedback. I think too often people get caught up in the numbers aspect of balance and difficulty, when I see it as a more mechanic oriented issue. Anyways, that is that.