The full screen issues, are not on my behalf, and is an issue with Unity. I belive hitting the escape key will exit fullscreen. The while you were away message is annoying, I agree, and I have not yet figured out how to have that only pop up once per session. I will look at that and see if I can fix it. You also said "son't use AI images", I was wondering if you could elaborate on that.
For one reason, AI images such as the one you're using for your game's cover right now often indicate to people that a game is low effort; games with AI covers tend to use lots of other AI assets (which it doesn't look like yours does), or possibly use basic game templates without adding a lot else to it. Even when this isn't actually the case, people are going to assume it about your game and not give it the benefit of the doubt.
Additionally, many image generation platforms take advantage of plagiarized art and are massively energy inefficient, and most people recommend avoiding them altogether.