The game does not support cloud saves
The game is not perfectly integrated with GOG
Support for MODs is not easy.
Honestly, the game lacks many points on the gameplay side.
The settlers are forcibly obsessive and paranoid in interactions with the goal of conquering Mars: the game is tiring.
The settlers prefer to renounce the objectives more than to get good results.
Extremely unrealistic
There are valid complains about the game regarding its EULA, mod support, etc that you can find in other reviews and should take into account. This one is about the merits of the game itself.
First of all, it's not an econ strategy and it doesn't play like a colony sim, though it can qualify as either if you squint just a little. It is a city builder with disaster mechanics cranked up.
A bunch of critical buildings and functions require human settlers and you don't directly control those. So a big part of the core gameplay is about attracting and catering to colonists, trying to nudge them into decisions aligned with your strategy. Which makes the game a city builder.
Another important thing to note is its pacing and depth. A normal playthrough takes around 20 hours. Even though it doesn't have the mechanical complexity of a typical 4X game, it does have a very similar pacing and variety of stategic choices.
Surviving Mars is an interesting concept and will automatically appeal to city-building simulator fans - though some may find it a little more difficult than your "typical" city-building simulator, largely in part because of the design concepts unique to Mars... Thankfully, the developers have rolled-out an in-game tutorial, so this should overcome this issue for most players.
At this time though, I still need to rate this "three stars" because at the time of writing, Surviving Mars does not "officially" support mods (as least on the GOG.com Linux version, anyway) and there's no "free build" option, to let players "just build" with most or all of the content unlocked and no money/resource restrictions... Sure, many people playing this will presumably love the strategy side of the game, but some players prefer to use city-building simulators as a Lego set of sorts, which is where a "free build" option comes in handy (side note - Cities: Skylines, which is by the same developer, has such an option).
Lastly, I want to point out that many city-building simulators over the years have offered little to differentiate themselves from the competitors and/or previous games, so Surviving Mars brings a breath of fresh air to the genre... And this point alone makes this worthy of a purchase.
Surviving Mars launched with a shipload of content ("shipload" - get it?) and all of the updates/upgrades to date have been free, so there's plenty of after-purchase on offer, for free thus far, too.
Anyway, check it out... You won't be disappointed.
The first part of the game is enjoyable. There really is a Marsian feel with excellent lighting, dust covering everything and rovers rolling over the bumpy, barren landscape. Setting up the settlement is exciting, but also the time of your first trials and errors. Some complain about the lack of tutorial: as a matter of fact, the lack of tutorial is entirely justified by the nature of the game: no one was there before! And the game mechanics are easy to understand, even if optimization is something to learn as you go. As your first colonists arrive, tension builds up as you try to achieve balance between resource production and availability – this tension will remain throughout and will likely keep you tied up to the game. All in all, this was conceived as an innovative city builder that still retains gameplay rules of the genre (like occasional disasters to thwart your comfort).
The game then largely becomes a game of resource management. The player is busy ensuring that all resource types are distributed where they matter, especially for maintenance. Colonists struggle to produce enough of the manufactured goods, while expansion is driven by getting more primary resources and building factories for other goods, in order to become self-sufficient before you run out of money. The technology tree is pretty standard, although in-dome buildings should be more thoroughly upgradable – like accommodations. Ultimately, the lack of feature automation can make it tedious to expand the colony on the map.
Although there is always something to do, I find that the overwhelming focus on resource management takes away great potentials to vary the gameplay and get more involved in the adventure itself. There are several flaws that further limit this. The skeleton of a scenario is one of them, and it is unfortunate that there is absolutely no politics at any level in this game. Other city building games do lack a scenario by essence (this is, after all, your own story), but more time spent on exploration with more discoveries and world events would already make the game more interesting… the explorer rovers are underused except for some scarce anomalies. Domes are basically a nice idea, but the way they are designed ultimately kills the immersion. You select lucky folks to take the first steps of humanity into the colonization of Mars, only to find out that you have to fulfill their need… for luxury and shopping! It seems as if people would go all this way just to reproduce a tasteless commoditarian society without any concern for the entire new world they live in – research is all melted together in a “research lab” building, and all the exciting aspects of learning about Mars are reduced to the meager central plot. These living spaces are also all too perfect – no need for waste management, etc. – which strongly contrasts with all the constraints outside of the domes.
This casual approach unfortunately breaks apart the only thing that holds this game together: the unique setting of Mars with its own challenges and rewards, and the adventure of living on another planet. The game’s identity is in everything around the domes – inside the domes, this could be any futuristic city building set up.
The colonists are otherwise differentiated by a few traits that are again very unimaginative and blunt (“lazy”?!) and it so happens that a great many of them are... alcoholics. Yes, really, it's one of the "flaws" and it's extremely common. This may not be what you’d imagine for a selection of people to send on Mars. To the devs’ merit, the domes’ names are by contrast more creative than I would have expected in this case.
In spite of this, it is still satisfying to see the colony grow and become more capable, and the game ends up being addictive anyway. I don’t think this goes much further than getting the biggest domes on your first playthrough, however, and the somewhat mundane domes would make you look back at your colony and wonder what the point of all of this was.
Game is intriguing, keeps you busy for days. It reminds of Civ V or Heroes III where I'd just say "Okay one more day and I go to bed" and it's suddenly 4 AM! The only difference is here you're playing against the harsh Mars environment and your own bad decision. And trust me... you will have plenty of bad decision. To get a grip of the game make sure you go through the training and don't start with 500% or more difficulty unless you know what you're doing.