I agree with sherbz, I also found Surviving Mars a bit slow. Pretty, good mechanics, but it takes awhile for things to happen. One of the few games where I'd say it's a bit slow for my taste.
I also highly recommend Factorio (though the price in USD is $30 now; it's probably £20?). Also one of my all-time favorites - I'm at a couple hundred hours, but expect to be coming back to it for a long time - and it has a demo, and it doesn't require Steam if you buy it through their website, so there's little reason not to try it unless you have important things to do with your time.