Conan Exiles!
I've been playing since beginning of April and it's the most fun I've had playing a game in years.
I'm playing it as a private co-op campaign with a buddy on default settings, and we're trying to discover everything ourselves without any guides. There's a surprising amount of content like dungeons, caves, and other things to discover that makes it very playable as a campaign, and it gives you progressively more difficult objectives ("Journey Steps") to complete that encourage you to learn and progress (though you're free to ignore them if you want). It almost feels like a hybrid of Breath of the Wild + Minecraft + Skyrim. (I can't speak at all for the PvP/PvE experience however).
There's even a mechanic that provides an incentive to build defensively even in single-player/private co-op mode, though we're still trying to build bases that look awesome in addition to being functional.
