Many people dedicate their free time with playing games or following game related activities. The Casual Games Market Report 2007 names games with more than 300 million downloads. Moreover, the Casual Games Association reports more than 200 million casual gamers worldwide. People play them for various reasons, such as to relax, to be entertained, for the need of competition and to be thrilled. Additionally they want to be challenged, mentally as well skill based. As earlier mentioned there are tasks that are relatively easy to complete by humans but computationally rather infeasible to solve. The idea to integrate such tasks as goal of games has been created and realized in platforms such as OntoGame, GWAP and others. Consequently, they have produced a win-win situation where people had fun playing games while actually doing something useful, namely producing output data which can be used to improve the experience when dealing with data. That is why we in this describe state of the art games. Firstly, we briefly introduce games for knowledge acquisition. Then we outline various games for semantic content creation we found, grouped by the task they attempt to fulfill. We then provide an overview over these games based on various criteria in tabular form.