Rincewind, thank you for the link to the German Blender Tutorials!
I just read in the last few minutes many things that makes things clear that I didn't really understand before.

http://www.puppenheim.org/
http://www.wuerfels-welt.de
Old Game Tutorial: http://www.puppenheim.org/MITutorial.zip
Free Game Editor: http://puppenheim.org/AlienalsWeihnachtsmann.zip
http://www.puppenheim.org/blender_starting_main_settings.txt