I think this is the first game that I've gotten all the steam achievements on! Adventure Capitalist!
It's a completely free game so anyone else can try and get them too. It's actually a really fun idler game, like cookie clicker(which I'm trying to get all achievements on too, but it's harder there).
It was pretty fun to get it. I'd log in a few times a day, click my way up towards building everything up. I completed Mars first, and then the moon, and finally Earth! Mars was very quick to finish, I think it was sub 24 hours actually. Moon took a few months and earth took a few weeks longer than that.
For a free game this gave me lots of fun! I think I'm going to be picking up another game to try and get all achievements on soon! Maybe I'll go for one of the Batman Arkham series game. I love the stories and gameplay there, but collecting all Riddler trophies takes eons!