Surviving Mars

Would only recommend the base game, green planet, and the mysteries DLC's, the rest are useless and overpriced

It's a casual city builder for space nerds. IT'S THE ONLY FICTIONAL WORK THAT SHOWS PEOPLE BOUNCING IN LOW MARS GRAVITY! It's super cool to build up several outposts of domes and to build up a fleet of reusable rockets that go back and forth to Earth.
But for how harsh surviving Mars should be, Surviving Mars is pretty casual. If you know how to balance resource production and make distributed rainy day stockpiles, you'll weather every disaster effortlessly. That is the totally 100% intentional artistic message, right? "Robots make Mars easy." Resources are a little too abundant, except for maybe colonists. Their mental breakdown mechanic of "renegades" is trivial to deal with. The diplomacy isn't the deepest, and it was pretty easy to destroying all rival colonies, if I wanted. They shrank the solar system to fun-sized, so the rockets make the round trip quickly enough to bail you out, instead of arriving with vital supplies only when everybody's dead. The biggest challenge is making your playthrough challenging, and any challenge you do find only really lasts through the early game. You're not making decisions of real consequence. I've done a few runs with hardly any deaths and zero colony failures. And yet, I still recommend this game.
There are a lot of event chain campaigns. They're fun. Since most of us aren't doing a dozen playthroughs, I would look up which ones are coolest and do those.
The Terraforming DLC adds a satisfying endgame. Somehow, a bunch of machines in one tiny village is enough to green all of Mars -- do the devs know how huge a planet is? Don't think too hard about it! It takes long enough that it still feels like a grand project. You do more than make percentage numbers go up: you take a barren planet, build a zillion terraforming machines, add lakes, and sow seeds. You are rewarded by a lush landscape of grass and trees, and finally, opening up the domes to the now hospitable sky. The second time around, it feels kind of tedious, until you try to make it as fast as possible by massively scaling up your operation.
If you want a deep and brutal city builder, play Frostpunk, Rimworld, or They Are Billions. If you're set on space, Oxygen Not Included has depth and personality, and your decisions can kill everybody. If you want to live the specific fantasy of a thriving Mars colony? It's pretty fun. And, somehow, replayable.

Its a nice game. Just avoid the Below and Beyond DLC; terraforming DLC is better.
I think the devs have abandoned this game though

I just decided I was tired of the Finals and Dota2 and picked up this game. Somehow in 5 days I've played 32 hours of this game. Idk see for yourself, but the other comments are valid about the publisher + the whole DLC package being worth almost $100. At this point I feel like they will get more sales if they just bundle the whole thing around $10-20. I would love to try out the DLC since this game is so addictive and relaxing but I ain't paying all that. A great game that you can pass the time on for under $5 now, it's already approaching the 5 year-old mark so fairly old.

This is a two-audience game - it's a light resource-chain survival game and a Martian city-builder. For a city building game it is harsh and carries the risk of death spirals and loss of your colony, especially if you have not developed your skills in harsher resource-chain games (I'm thinking of Banished, Oxygen Not Included, Rimworld, and others). The game is absolutely beautiful but is not a freeform city builder in standard mode - sandbox might be an easier introduction, or the scenarios might teach you a thing or two about colony survival games.
And yet for a survival resource-chain game about a settlement, the complaint is that it is fairly light on challenge even at high difficulty settings. There is no global difficulty setting, but a bunch of challenges you can take on to make the game harder and increase your score, a kind of a la carte difficulty setting. As someone with something like 20 restarts each of ONI and Rimworld, and who eventually kind of tapped out on both due to game-life balance, Surviving Mars is a really satisfying balance of challenge and aesthetics in a gorgeous sci-fi setting.
I get it if it's a little disappointing to people for whom Dwarf Fortress is easy that such a gorgeous game would provide relatively uncomplicated challenges. There are only three advanced resources, so the logistical complexity is comparable to, say. Transport Fever 1 or 2 - which might seem like a piece of cake to Rimworld/ONI/Banished/DF folks.
For the rest of us, yes, a 400-500% difficulty game is a relatively serious challenge, and one which is rewarding and compelling amidst the vast red vistas, realistic low gravity portrayals, etc. This game has a medium amount of crunch and challenge for those who like resource-chain economic/strategy games, and is set in a compelling visual, auditory, and conceptual atmosphere. A city building/logistics fan might find it too unforgiving, and a survival colony games fan might find it too easy. To me, it's an extremely happy medium and an excellent game, where collapse is a real threat amidst the desolation of the Martian landscape, and to build a thriving and beautiful community is highly satisfying.

This is a pretty amazing game as long as you get the "Green Planet" DLC with it. You start with a rocket, some drones, and a few options for loadout and try to maintain a lasting colony on Mars though weather, climate, natural disasters and and unique sci-fi story challenges. If you have Green Planet as well, you can also fully terraform Mars to have plants, water, and breathable air.
The game can stay fresh for multiple playthroughs as your starting loadout can affect your entire game with certain perks or difficulties. In addition, you're able to pick to start anywhere on the planet which will affect not only your natural benefits and difficulties, but also which "breakthroughs" you're able to get. Breakthroughs represent unique technology which can change the game entirely. All and all, this was money well spent and is my go to game whenever I want a peaceful challenge or a break from other games.

I definitely recommend the game for those looking to scratch that sci-fi city builder itch. However, there are some things you should keep in mind if you want to buy it. Firstly, the game is considered to be in a "finished" state, and as such it won't receive any more updates, major or minor. Secondly, the game includes several DLC packs. The only one I'd recommend buying at full price would be the green planet dlc, as its the most fleshed out of all of them. And in regards to the other DLC's, I'd recommend picking and choosing them at your own discretion, and ideally waiting for a sale before purchasing.