when contacting a sponsor do I have to upload a demo-version of my game or the full version? I just ask because it's the first time that I do this kind of stuff.
It really depends. If you want to submit the game on fgl.com then you should put on the full version and wait for a sponsor to place a bid. If you want to ask a sponsor you've worked with or another sponsor you can ask(Such as Miniclip) if they would like a game like that, then you could make a prototype/demo of the game and if they like it you can continue working on it.