It is a particularly nasty Friday afternoon. There is a thunderstorm going on, the likes of which you have not seen since the Brother-in-Law of Frankenstein, and you have gone out to buy a litre of milk. Being an idiot, you have forgotten to take an umbrella with you, and you are getting wet. Just wait! Just over there is a convenient flying saucer! Surely no one would mind if you took cover inside until the storm passes...
Notes
The original C64 version was released as public domain. (In the early 1990s?)
Weird game... Really weird!
It is the first one about cleaning up something in order to win...