(Hopefully I didn't miss a thread about this game)
It's a coop survival game released this month by a tiny Swedish studio, and it has sold more than 4 millions copies already.
Building houses, traveling the sea, exploring procedurally generated islands, fighting bosses, crafting, killing mobs, going in dungeons, harvesting...
It looks pretty good I think with the lighting system and visual effects. Everything is pixelated though so not everyone may appreciate the art style.