In Thief Assistant you're trying to collect all the jewels in each level in order to help the thief with his heist. The object of the game is to clear all the jewels. If you have a collection of three or more you can click on them and they will disappear. The trick is that the color gems are often interlocked with other colors and you need to be able to make the gems disappear in the right order. You cannot have any gems left over at the end or you will have to restart the stage. This is trickier than it sounds and is tons of fun so play Thief Assistant now!