If you're travelling, you may already be thinking in advance: "What gifts will I bring home? And do I have enough space in my suitcase?"
It's not always the case that the gifts you bring home will raise the eyebrows of those at home and the recipients and bring tears of joy.
Or have you ever thought about whether the wife of an astronaut would really be happy to receive a bag of moon dust?
The following reaction is more likely: "Moon dust, great. I hope it matches the colour of the dust in our flat. Can you give it back if necessary?"
These thoughts were the basis for this little video game.