Download the demo from
http://no-fragments.atari.org/no_fra...T/WAITFALC.MSA and press [F2] when promted to select Atari STF or STE.
Here's an animated GIF I created to show you the screens which are displayed after booting the demo:
If you mistakenly press [F1] at the beginning, the demo screens will be shown one after the other without the "Ghost Battle" main-menu.
I used STeem.