I've changed the main menu screen with Xardas. Here is the file. You should have Gothic3 Starter to run it. To install it extract the zip file to your GothicIII>Modifications folder. In Gothi3 Starter click Xardas Menu box and run the game. Here is a screenshot: http://www.geocities.com/vagospap/MainMenuAfter.JPG
And here is the tutorial: http://www.g3-modding.tk
So what do you think?