In the Unstable Branch (as of version 1.5.1) we are currently testing wide screen support and how the game plays without an UI. In this mode the UI will automatically hide, but pop back when needed. For example when opening a chest, inspecting your map, or pausing the game.
This gives you an uninterrupted view of the game, allowing you to keep an eye on what really matters...
The mode is optional, in the options menu you can chose to disable it if you prefer having your inventory, map, and status visible at all times. There is also the option to hide the entire UI except the minimap, and there's even the option to toggle between the two modes by binding a keyboard key.
It's all still in an experimental state, so your feedback is definitely appreciated!