GUI
Probably a tad confusing, so...
We shall use the basic GUI as an example.
The slowly back and forth moving Toribash logo is GUI Logo.
The text TORIBASH and Violence perfected is GUI Header.
The red area and the shadings is GUI Background.
The blood on the bottom right corner of the GUI Background is GUI Splatter.
With these, you can change the main menu in game for yourself.