The demo switches to full screen at desktop resolution automatically. There is no windowed mode.
The demo places you in a random maze level which can be one of the easy, tough, or extreme mazes.
Use the arrow keys or left/right on a supported X-Input controller to navigate to the exit.
Pressing the 1, 2, or 3 keys will switch to a random easy, tough, or extreme maze respectively.
Pressing escape will exit the demo.
A few debug keys may have been left in (hint try P ;-)).