Twelve Free Games For Christmas!" series is a fun stealth game called "Trilby: The Art of Theft" by Ben "Yahtzee" Croshaw.
You play a master thief named Trilby. He prides himself on on committing the perfect thefts. Your goal is to avoid detection, disable traps and alarms, pick locks and steal the good stuff. The better you are the higher your score. There are also items you can earn.
"Trilby: The Art of Theft" is one of those rare games that makes you keep coming back to try and get a better score. So download it today and see how good you are. Available for PCs only.