Hi,
I'm interested.
My bid is for the Levelmanager/Tank example you provided and assuming only ready made art assets are to be used. If you need assets built or drawn, I can provide that too, but price will go up.
If you need more logic like enemy spawning, tank shooting, score keeping etc., that may need more effort than what the quote was provided for.
Also, depending on how you want the assets to be integrated, some may require more work than others, so I'd need to look at every project separately before providing a quote.
We can also converse in german, if you prefer that.