Why can the game not be opened?
If a black window with a small red cross in the left upper corner is visible on your screen, Java is not installed or activated. Your computer requires Java to "understand" our games.
A link to download a suitable version of Java can be found here: http://www.java.com/de/download/windows_automatic.jsp
Please enable Java in your browser (in 'Internet Options' under 'extended') following the installation of the software.
Finally disable the Java caching function in the Windows control panel under 'JavaPlugin' and 'Cache.' Now you should be able to open and play our games.