Originally Posted by Arkadia7
I think what the game reviewer meant by "empty" is that the game world felt empty to him, in that there weren't enough people around, and also, specifically, that there wasn't enough flora and fauna around in the game world as he was exploring it. He actually mentioned that in the video. Like - birds, farm animals, deer, other wild animals in the wilderness that were missing - that kind of thing.
More of this would be fish swimming in the rivers/lakes that the player can see (maybe they have this already in the game) and bees buzzing around, along with the odd annoying fly every now and then…the wind blowing hard on occasion (infrequently), causing the trees and bushes and such to noticeably sway in the wind…all these small environmental type details, like as mentioned above, the Witcher 3 did so very well, are extremely important to the ambiance and atmosphere of the world. To make it "feel alive".
I don't think he meant that there are no places to discover or explore. More of a "the world feels too empty" type feeling.
This could be fixed by a future patch or mod, obviously. As could many of the bugs.