Hey there, thanks alot for the bug reports and I'm glad you like the game! :)
We're aware of both of the issues and are working on a fix of the first one. The fullscreen thing is sadly a unity thing and hard to fix from our side, but we might have an idea on how to go about it.
Once the game is finished (oh man I can't even imagine how long that will be, haha) we've got some ideas on what to do. We will definetly keep releasing the new versions for free. We might release an directors cut or whatever you wanna call it on steam for some price and give keys to everyone who donated a set amount before. But, again, this is far in the future and we're not sure on how this will work exactly.
Glad you like the game and thanks alot for the feedback! ♥