Defend your castle
http://www.albinoblacksheep.com/flash/castle.php
I play it now and then, few times i've lost a couple hours by accident just from the addictivenes... the point of the game is to defend your castle by picking up stick figure people with your cursor and dropping them from a high height... you can buy upgrades with the points you get to have archers and mages to defend your castle and can get craftsmen to repair your castle, its fairly simple. Just read the help part before trying.
-Alz