a few words regarding the steam keys:
There is a simple reason why you wont get a steam key if you download the game for free: g2a or kinguin.
the game is 5,99 on steam. who can guarantee me that the steam key wont be sold on one of these platform? I have no problem with people getting the game for free or even pirate it - all fine for me. but i have a problem with g2a and other people making money with my work. So i am sorry.
I also couldn't put up the game for free on steam - you can suggest a price for your game and valve has to accept it. in my case it got denied for whatever reasons. So i hope you can understand this. have fun with the game :)