From screenshot:

  "Press  to stop game"

Funny how much sense that makes in a twisted way. I was thinking that they had some kind of functionality that had you attach text to a keyboard event to explain it. Alas.

  GraphicsWindow.DrawText(x, y + 320, "Press to stop game")

It's just a ... feature.

Edit: and the key they hooked up "stop game" to was not space, it was escape :(