ReROLL isn't like most survival games. For one, it uses drones—the machines map out the games' world using real-world map data. Which is to say, the open world you'll be exploring in-game is some of the terrain you'll find in the real world.
Beyond that, the weather and temperature are pulled from the real world too - so if its snowing in Toronto in real life, it'll be snowing in Toronto in the game, too. It doesn't sound like society will match ours, though—that's why you have to scavenge, craft and survive. Also, there are mutants for some reason. Hey, it's a (PC) video game. Naturally, there will be other humans you have to watch out for too—and like other survival games, it may just happen that other survivors are the thing you have to fear the most.
The game is being developed by ex-Ubisoft developers who have worked on games like Assassin's Creed and Far Cry. The game won't start out having the entire planet, since mapping it all out takes time—but this ensures that the developers will be able to give players a steady stream of new locales/content.