The Adventure Game1980

Opening narration:
[FIRST SEASON] Many light years away, on the far side of the galaxy, in a region often visited by time-travelers, lies Arg. A small planet of little consequence. Naturally, the inhabitants of Arg get a bit fed up with trippers and tend to discourage them. Often they will even nick the essential crystal off their time machines and hide it. Visitors from planet Earth enquiring after their crystal can nevertheless feel quite at home here, because the Argons are a polite race and careful to adapt their shape so as not to frighten strangers. Unfortunately, they also have a regrettable sense of humor...