PLANET OF DEATH - TESTING BRIEF

This is a port of a game from the early '80s in the UK - Adventure 'A'
from Artic Computing. It was originally released on the ZX-81, and
subsequently on the ZX-Spectrum.

As a port, the goal is to preserve the original game. So the room
descriptions are largely unchanged, and a walk-through from the
original game should work on the Inform version.

I have changed the descriptions from first to second-person
("You are on a mountain plateau", rather than "I am ...").
Other changes which I think are acceptable:
    - improving the interaction
    - sensible responses for all appropriate actions
    - fixing things that were probably bugs in the original