From the blog "Sandbox Update Notes"
+ Added inventory and hotbar systems
+ Added weather status UI - displays altitude, humidity, and temperature
+ Added decorators to world generation - decorators refer to small ground details, such as flowers, pebbles, etc
+ Added resources to world generation - this currently only generates trees, but will generate other resources in the future
+ Added world features to world generation - this refers to any sort of premade structure which can generate within the world, with the