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People who like engineering/physicsy simple computer games
You might not be old enough to remember this game:
http://www.bestoldgames.net/eng/old-games/the-incredible-machine.php
But it was fucking great. You may need to grab DosBox to run it http://www.dosbox.com/download.php?main=1 but I found it ran in XP, despite a garbled intro opening.