I have a duplicate key for that game, so I am giving one away for free. I played this game already and I think it was good: https://store.steampowered.com/app/746850/Cloudpunk/
To get the key you have to submit your email here: https://www.humblebundle.com/gift?key=ZWyyc2Su7BNBpr7z You might have to register too, I don't know.
First come - first serve.
Cloudpunk was good but I wouldn't classify it as fun. It's one of those games that would have been better as a movie because it's gameplay was average at best. I hear there's a sequel coming out which I hope is better since I really liked the setting of the game.
On another note, I've never thought of giving away extra keys online before. I might have to do that with some of my keys.