There are many different reasons that people play games, and just as many different kinds of games to accommodate those tastes. However, one of the most popular reasons is challenge. A lot of gamers simply love the satisfaction that comes from beating a particularly tough level. But this doesn't always have to mean violent gameplay where players are forced to do battle with waves of enemies. In fact, there are plenty of games that challenge players' ability to solve problems, albeit in a fun and exciting way. Here are a few such games, as well as links to their individual What They Play pages, which will provide further information.