Interesting little game - I was just trying it out. Looks like an actual bug, I managed to find myself outside the maze and walk around? And when I moved around the edge to the top of the screen I could collect the 5 blue what look like jugs and they were added to my score. I think I was exiting on the left but could have pressed one of the function keys at the time. Once outside you can't get back inside. Edit: I did manage to get back inside later on after more testing if I transformed back into a ghost. 