The game is good once you get the hang of it, but there are bursts of micromanaging followed by long droughts of waiting for shit to happen. At max speed, the game will do 1 day/3 minutes. Most of the Steam achievements take about 60-100 days to do, which means 3-5 hours per game with lots of time spent not interacting much. Of course, to get to a "full fledged" colony it can take as many as 10 hours of gameplay, which again is mostly waiting for your commands to happen.

Also, because its a Paradox game, the interface is ass.

If you like the genre of games, this is one to lose a couple of dozen hours to. If you just think "oh, Mars is cool" its probably good to skip or download a mod that lets you zoom time faster.