So this releases today and looks like a pretty good time waster, and if you own Cities Skylines you can get 10% off. Made by Haemimont Games (Tropico 4 and 5) and published by Paradox. I might pick it up in a few days.
It is essentially sim city on mars. There's a fairly long build up part to getting the infrastructure in place before any colonists even get there. When they do finally get there, it turns into making sure they have everything to keep them healthy and happy.
So I bought this and have played a bit...it has some flaws but there is potential. Biggest issues I have found are: unable to connect domes, cable/pipe management, and people management. Sometimes your people will change jobs and there's no way for you to stop them or change them back, other than fire everyone else who moves into that job until another specialist takes it. My botanists decided to sell electronics instead of growing food and my scientists went to work in the mines, and the engineers went to grow food. They still produce everything but not as efficiently. It is very annoying. After reading a few reviews it seems others have the same complaints. Hopefully Paradox will get this straightened out in a patch. Lots of mods are already out, so maybe some of those will fix some of the issues.