Game developers make heavy use of "metrics" in order to understand how their games are being played by the public. Through recording players' actions within a game, designers can identify weaknesses in the game design, such as sections of the game that are too difficult, or never explored. We have created an open source game analytics service called "RedMetrics" in which all data gathered is freely available online. RedMetrics can gather data from any platform (web, PC, console, etc.) and stores it an open repository. The data is available via a web API as well as a web application. To ease integration, we provide interfaces for the popular game engine Unity as well as for the web browser.