Gunplay was definitely more than solid ( and I played my share of FPS) ...not exactly F.E.A.R, Black or Killing Floor 2 quality, but well above gameplay in nearly every rpg. Hell, if rpg has even decent gameplay, we can proclaim a miracle.
AI? Went too fast to tell, I think this and stealth are very much WIP. And you can definitely see, they're still working on UI, hacking, some animations, car physics.
But what it stands out is how open everything is: vertical levels with multiple entry points, hack into and mess with the enemies, parkour, climb across or destroy walls ( anyone who played R6S, knows what this does to gameplay), multiple firing modes, melee, etc, etc...seems like a playground for coming up with creative methods to overcome obstacles.
And quest branching based on narrative choices. This kind of blend of rpg and Immersive sim hasn't really been done before. Plus a GTA scale city with plenty of explorable interiors.
And I really like the characters/dialogue/slang, variety in how npcs look. Feels like a place brimming with attitude, character. Which is pretty much the core principle of 2020.