It would be nice if you ask me before uploading a project that is majorly a copy of my game. Or at least you could say it in the description of the scenario.

Is the fullscreen also working when you export the scenario to a runnable jar file? Because my fullscreens (http://www.greenfoot.org/scenarios/9164) only work when I upload the game or execute it in greenfoot. And is there a way to download Greenfoot3D? I couldn't find one.

You can either encrypt your user image when you play online or you can use any image you want if you download it. Just choose the image you want in the dropdownlist, write the text you want to encrypt into the 'Encrypting Text' field, add a password in the 'Password' field and click on encrypt image.