From what I can see, they're looking at a single player game with the option to coop. I don't think that they're trying to compete in the Rust and DayZ space. They are also projecting a mid 2015 release date for their first playable version which will be just a couple square miles.
If you look at the scope of the entire project they want to build a game that accurately models the entire planet to scale, uses real world weather that is accessed via the Internet, is crowd funded and playable on "older machines". I have my doubts as to how this is going to pan out, but it looks awesome and I'm hoping that they can pull it off.