So from what I’ve seen of the gameplay it looks like the world will be a bunch of zones stitched together consisting of an outer world that can have more multiplayer instances such as events/bosses and so on. I think the dungeons themselves you’d have to organize a group to play together though that is merely speculation.
Most likely throughout the world there will be a certain region or biome that will then consist of these zones which will have the over world events (bosses/events) and some quests for both dungeons and the over world as well. As an example you could have like 4-5 regions showcasing different sanctuary locations and then each of these regions would have maybe 5+ zones each. Each zone would have an over world consisting of maybe 3+ events (boss fights / events), quests and then dungeons interspersed with enemies to kill, chests, and the fantastically new and never before seen feature: Climbing/Horseback Riding. Please note this is just my guess but if that is the case to me that kinda sounds rather generic and rather boring but hey we’ll see what happens.
World boss I saw like 10 or so players clustering around 1 large boss with attacks that weren’t choreographed well. What I mean is that with 10+ players fighting this boss you’ll have a ton of effects going on and it can be difficult to gauge what the bosses move set will be. Lost Ark I found an example where some hard hitting attacks would make a red highlight on the ground giving the player knowledge of what is to come. To me having 10+ characters surrounding a chunky monster wouldn’t look good and wouldn’t play good either (monster aggro harder to read, attack difficult to see and so on). I could see there being a way to do this but it would be rather unique and unsuited for the Diablo Universe.
Music being like D3 where it’s all in your face orchestra and dramatic rather then in the background emphasizing the actual game when it comes to atmosphere. For boss fights yea I can see D3 style working well - in a random dungeon no. This is just in general. I’ll probably recheck some gameplay videos to get a better sense on the ambient music.
Lighting. Rather minor but it kinda bugs me when I see random candles lit around a dungeon and yet there are zero humans around so… why the candles? Ambient lighting, monster influenced lighting (bonfires and the like), and environment (bugs, plants, animals), magic lighting can all work but seeing repeated candles lit like your on some sort of walkway doesn’t make any sense at all.
Color pallet being a bit too gray or brown in the environment. While I don’t want rainbows like D3, color can be used even sparingly to add a bit more contrast in an environment.
Druid and Barbarian having some odd sort of combo system when it comes to shape shifting or using dual wield / 2h. This is from what I saw with pre-determined skills so hopefully that won’t be enforced with the skill builds.
Narration / Dialogue / Story. Major concern if anyone remembers Diablo 3’s dialogue - it was rather bad most of the time and borderline atrocious the rest of the time. I’m not sure if Diablo 3’s dialogue was done in the way it was done to emphasize a more immature crowd but if it was I wouldn’t be surprised (much like the cartoony look). Hope we won’t get some stupid villain telling you his most nefarious plan and how you can stop him…
In any case, just some thoughts. I will remain skeptical when it comes to whether Diablo 4 will be good or not. I hope that it would be but this is Blizzard Activision and we have Diablo 3 to remember.
edit: I wouldn’t be at all surprised if Blizzard back in 2018-19 used Diablo 3 as a base for Diablo 4 in order to try and copy other more current ARPG’s (Lost Ark 1 example). Backlash from Diablo Immortal making Blizzard scramble to not lose their fanbase resulting in Diablo 4’s development being super quick.
The shown gameplay video could easily have been cobbled together much like Diablo 3’s to give the false impression that they have a ton already done. And yet Diablo Immortal backlash with Blizzard giving zero reassurance of a PC Diablo game. And yet when asked about a release date it was heavily implied it would be longer then Blizzard’s idea of soon (so like maybe 2 years from nowish).