The first thing I noticed? It’s kind of hard! Harder than I remember, and I recall the uh, “fun” chase of dying to a powerful enemy, then being asked to stroll by that powerful enemy naked to reclaim your gear, which often does not go well. This is not about fixing Diablo 2, this is about rendering it as accurately as possible with just a few concessions, like free respecing. Like obviously they could have dramatically increased inventory size if they wanted to here in 2021, and yet things like that are kept to retain the “charm” of the original.
Above all else, the most maddening thing to manage is the extremely tiny inventory screen where you can’t hold more than a scarce handful of armor or weapons at a time, requiring frequent trips back to town. Going back to scrolls for Town Portals and identifying items. But if you’ve been playing Diablo 3 for the past nine years, you will obviously miss some of the quality of life upgrades that game brought with it.