Procedurally generated world (with quests designed in the same sense). A bit like The Forest or more akin to Stalker. You're in the world where you need to survive. Not sure will there be "main quest", from what I've read there won't be such a thing. Enemies are zombies or mutants or whatever. Game is strictly singleplayer.
All in all, typical rogue-like survival single player game set in irradiated apocalyptic world with zombies/mutants as main enemies, with some very advanced physics.
Shame he didn't go for full realism. His wood chopping animation is good but there could be more variants of that animation. Also, trunk should fall and stay there so player could chop it just like irl, into planks. Similar should be done for lighting fire. If he went through all the trouble to simulate wind and wood catching fire in realistic manner he could make it so you hold a fire source in order to put plank on flame, instead of just picking option from the menu. When you go into such tiny details, better make sure you go all the way
