I found out during my Utah Python meetup that the game I created called Cows and Bulls is actually called MasterMind in the US.
It's a really simple game.
The computer thinks of a 4-letter word. You start guessing that word and the computer will give hints along the way.
Cows - Number of characters in your guess that match the original word, but placed in a different location.
Bulls - Number of characters in your guess that match the original word, found in the exact same location.
Based on the hints from each turn we can narrow down the possibilities and finally reach the answer.
It's a fun game and really easy to implement.