I've been playing for nearly a month now and I feel like I've completed less tan 10% of what the game has to offer; much of the map is still blank, and I'm only at the second temple.
The game is unbelievably huge. But unlike so many really big games, pretty much none of it feels wasted, there's always something to find or do no matter where you go, whether it's a cave, a miniboss, or a falling rock that will take you up to a new sky island. It's not just big, it's dense too, packed to the brim with content, almost all of it top notch.