Decent enough game. Not so much surviving mars, as learning how to cope with building a city on a planet that occasionally tries to kill you. Surviving is never a question, rather it's building up your robotic infrastructure before bringing colonists and feeding them before the money runs out or a meteor destroys your O2 or water extraction and delivery. The "mysteries" are good flavor on the game, and range anywhere from mega-easy to devilishly hard. Breakthroughs are fun and can have a major effect on gameplay and the success of your colony. I've never had a total colony collapse without my direct, deliberate intervention, somewhat similar to those of you that build your Sims a pool, and then remove the ladder...leading to multiple drownings.

Green Planet adds a fun and grand diversion of trying to turn Mars green. It's a slow process, and I've never played it beyond growing simple grass and attempting to create a lake that refused to be anything but ice, but I've seen plenty of screenshots with beautiful juxtaposition of red ground and green foliage. Recommended.