Terraforming Mars Solo Review: Why Engine Building Creates the Perfect Optimization Puzzle

Terraforming Mars At A Glance

After thirty years in the field of accounting, I figured I would put all my spreadsheets, budgets, resource allocation, and optimization problem-solving skills on ice after I retired. But, I had no idea I was really training for a hobby I wouldn’t find until later – playing Terraforming Mars.

As of today, I’ve played Terraforming Mars 142 times. I track my win/loss percentages using different corporation combinations, card pools, and the difficulty settings of the solo mode. I’m currently working on a spreadsheet to determine which production chains will produce the greatest amount of exponential growth. I’ve played Terraforming Mars so much, I can look at my hand of seven cards and quickly tell the best possible sequence of actions based on the optimal mathematical sequence of actions. And the thing is – I still discover new synergies and engine combinations every week.

Terraforming Mars is an engine-building game — essentially, you’re creating systems that create other systems that create even better systems. You’re optimizing resource flow, you’re managing probability, and you’re deciding between short-term survival and long-term exponential growth. If you enjoy the satisfaction of balancing a perfect budget, or watching compound interest grow your investments, Terraforming Mars will consume you.

However, the true power of Terraforming Mars lies within the solo mode of the game. Not in the sense that the solo experience is just as good as the multiplayer experience, but rather that the solo experience fundamentally alters the way you approach the game in ways that multiplayer cannot.

What Terraforming Mars Really Is

You’re a megacorporation that has been chartered to terraform Mars. You play cards (representing projects), spend resources (money, steel, titanium, plants, energy, and heat), and attempt to increase Mars’ temperature, oxygen levels, and ocean coverage to levels suitable for human habitation. You receive points for accomplishing these feats. Whoever reaches the highest terraform rating wins.

That’s the top-level explanation. The game itself is about building an engine. Every card you play creates production — resources generated automatically at the end of each turn. Early game, you’re playing cards that are expensive and provide a small amount of production. You’re surviving, not thriving. Mid game, you’re playing cards that will amplify your existing production. You’re not just producing resources — you’re generating the means to produce resources. Late game, your engine is running at full throttle. You’re playing multiple cards per turn, producing massive amounts of resources, and watching your score grow exponentially.

A big part of what makes Terraforming Mars brilliant is that none of this is hidden or abstracted away. You can see exactly how your production is going to work. You can follow the exact chain of logic that led to the discovery of a particular synergy. And unlike many games, the production aspect of the game is entirely deterministic — once you’ve created a particular production path, you’ll get the exact same production results every single turn. Randomness enters the picture when you draw cards, and even that is relatively controllable if you understand the nature of the card pool.

Why Multiplayer is Good; but Solo is Better

While Terraforming Mars is a solid multiplayer experience, it’s certainly better in solo mode. In multiplayer, you’re competing against other players for limited resources. You’re racing to claim project spaces before someone else does. There is some legitimate tension — you want to play a card, but another player is developing a similar engine and will likely prevent you from achieving the same production.

While multiplayer Terraforming Mars isn’t terrible, it’s not pure optimization either. Other players introduce random elements into the equation that you can’t control. Another player could play a card that makes your entire strategy obsolete. The order in which players act affects access to cards. Luck of the draw can allow a player to develop an engine that is significantly stronger than yours.

Solo mode eliminates all of these issues. You’re not competing against other players. You’re not being hindered by other players’ strategies. Instead, you’re competing against a threshold — you must achieve a sufficient level of terraformed Mars before your deck runs out of cards. Simple. Clean. No variables outside of your control.

This dramatically changes the way you approach your strategy. In multiplayer, you may be hesitant to play a card that you believe is “aggressive” — a card that produces a ton of resources but doesn’t give you any points right away. Why? Because you know other players will exploit this weakness while you build. In solo, you can be as aggressive as you want to be. You can spend twenty turns developing an engine that produces a ton of resources, but doesn’t produce any points, because you know by the time you run out of cards, that engine will produce more points than any conservative strategy.

The reason Terraforming Mars is so addictive is due to the fact that it offers a unique type of puzzle — an engine-building puzzle. What is an engine-building puzzle? An engine-building puzzle is a puzzle in which you must build a series of systems that ultimately interact with each other to create a larger system that generates the desired outcome. Think of it like building a train engine. First, you need wheels to move the train. Next, you need a motor to turn the wheels. Finally, you need a fuel source to drive the motor.

Now imagine this same process, but instead of wheels and motors, you’re building a network of resource-producing systems that feed into each other to produce an ever-increasing amount of resources. That’s an engine.

Engine Building Puzzles in Terraforming Mars

Let me illustrate what an engine in Terraforming Mars actually looks like. Let’s assume we’re playing Ecoline, a corporation that specializes in plants. We begin with a very weak production base — 3 megacredits, 1 plant, 1 energy, and 0 steel.

Turn 1: We play a card that costs 5 megacredits and produces 1 steel per turn. Our current production totals 3 megacredits, 1 plant, 1 energy, and 1 steel per turn. Clearly, our production is extremely weak. We’re barely covering the cost of the card we played.

Turns 2-3: We begin to play cards that amplify our plant production. Perhaps we play a card that costs 10 megacredits, but produces 2 plant production per turn. Now we’re producing 3 megacredits, 3 plants, 1 energy, and 1 steel per turn. We’re still quite far from achieving the production needed to sustain us.

Turns 4-5: We begin to play cards that convert our plant production into megacredits or trigger when we use plants. At this point, our plant production (which previously appeared useless) is producing megacredits. Our total production is now 6 megacredits, 4 plants, 1 energy, and 1 steel per turn.

Turns 6-7: We’re now playing multiple cards per turn. Every card we play causes additional cards to be triggered. We’re using our plants to produce forests (scored points). We’re generating megacredits from those forests. We’re using those megacredits to buy more cards that will further amplify our production. We’re entering an exponential phase of production.

By Turn 8-10, we’ve achieved escape velocity. We’re producing such an enormous number of resources per turn that we’re able to play 3-4 cards per turn. Our engine is self-sustaining and continues to grow in strength and efficiency. We’re no longer concerned with simply surviving; we’re looking for ways to achieve the maximum possible score in the minimum number of turns.

This is the experience. This is why people continue to play Terraforming Mars over and over again. While the theme of the game (terraforming Mars) is interesting, it’s not the primary focus of the game. The main focus of Terraforming Mars is the engine-building experience itself.

How Solo Mode Creates a More Pure Optimization Experience

When you play Terraforming Mars in solo mode, you remove all of the complexity introduced by other players. You’re not competing against opponents. You’re not being hindered by their strategies. You’re playing against a single threshold — you must achieve a sufficient level of terraformed Mars before your deck runs out of cards. That’s it. Pure optimization.

With this type of optimization, you can finally see the quality of your engine. In multiplayer, you may have built an incredible engine, but came in second place because another player got lucky. In solo, if your engine is strong enough, you win. If it’s not strong enough, you lose. The feedback is immediate and unambiguous.

The Production Economy: Why it Feels Fair

One aspect of Terraforming Mars that I personally appreciate from an economic perspective is the fact that the production economy in the game provides real and tangible limitations. Resources aren’t infinite — you have a finite number of production points available. Every decision you make regarding resource distribution affects all subsequent decisions.

During the early game, you’re competing for the most efficient production. You want cards that produce a significant amount of production for a low cost. During the mid-game, you’re competing for cards that amplify your existing production. You want cards that will multiply the production you already have. During the late game, you’re competing for conversion cards — cards that enable you to utilize the abundance of resources you’re producing to gain more valuable resources.

The cost curve of the game is structured beautifully. Cards that are inexpensive during the early game tend to produce less production than cards that are more expensive in the late game. However, the cards in the late game produce more production per unit than cards in the early game. This structure prevents the game from becoming trivial — you can’t bypass the early game by purchasing expensive cards. You must progress through the curve.

The solo mode of Terraforming Mars demonstrates this clearly, as you’re making purely mathematical decisions. Does this card produce enough value to justify its cost? Will this synergy scale well during the late game? These are the only questions that matter.

Additionally, the production economy in Terraforming Mars is inherently solvable. Even if you fail to meet your goal, you can always determine why you failed, and therefore, make improvements for future attempts. The feedback loop in Terraforming Mars is both direct and instantaneous.

Setup & Play Experience: Why Solo Works Logically

Another benefit of playing Terraforming Mars in solo mode is that setup and playtime are extremely fast. Setup is minimal — you only need to prepare your corporation board and draw a hand of cards. Total time: ten minutes. Possibly less if you’re familiar with the game.

Similarly, playtime is highly efficient. While Terraforming Mars is infamous for taking an excessively long time to complete in multiplayer due to the time required for each player to evaluate their options, this is not the case in solo mode. Since you’re the only player, you can take as long as you want to analyse your moves without wasting time on unnecessary communication or coordination with other players. However, you can also choose to play quickly and complete the game in sixty to ninety minutes.

Lastly, the overhead associated with the rules of the game are minimal. The solo version of Terraforming Mars doesn’t require an automated system or additional rules to manage the solo experience. You simply play the game as normal, but instead of competing against other players, you compete against a scoring threshold. The official rules of Terraforming Mars are approximately one page long. Two pages, at most, if you desire a detailed explanation of the different difficulty levels.

Simplifying the rules of the game allows Terraforming Mars to get out of your way and let you focus on optimizing your engine.

Replayability: Why You’ll Play Terraforming Mars Over 50+ Times

I’ve played Terraforming Mars 142 times thus far. While I’m confident that I’m among the top 100 players worldwide, I am far from the only person who has reached this milestone. I know several players who have eclipsed 300 plays of Terraforming Mars.

There are numerous reasons why Terraforming Mars is so replayable, including:

Each of the five starting corporations in Terraforming Mars behaves uniquely. Ecoline uses plants, Interplanetary Cinematics uses events to generate megacredits, Helion uses energy and heat, etc. As a result, each corporation represents a unique engine-building strategy.

With nearly 200 cards in Terraforming Mars, and only 50-60 cards drawn per game, you will almost always encounter a unique set of cards in each game. This leads to the frequent discovery of new synergies and engine combinations.

Finally, Terraforming Mars has variable difficulty scaling. Are you struggling to reach the scoring threshold? Try a higher difficulty setting. Have you made it too difficult for yourself? Try a lower difficulty setting. The game accommodates whatever challenge level you prefer.

Additionally, after you’ve completed the solo challenge at your preferred difficulty level, you can add your own personal optimization challenges. Can you beat the solo challenge with a specific corporation? Can you achieve a specific score? Can you develop a specific engine combination that should theoretically be impossible?

These are the key differences between a good game and a great game. A good game you play 20 times and set aside. A great game you play 50+ times and continually discover new aspects of the gameplay. Terraforming Mars is a great game.

Is Terraforming Mars still a Good Game in 2026?

Yes. It has been since its release in 2016. Dozens of new “engine” building games have appeared since then; none of them have achieved what Terraforming Mars achieved when it comes to combining a clean and beautiful engine building mechanism with high replay value and pure engine building satisfaction.

As for quality of the components, the cards are a good size, there are no decorative cards or other frills, the illustrations are nice but simple, and the rule book is very clear. There are also many expansions available which add a lot to the base game while not making the game too big.

My only negative comment is that the game can be long (i.e., take hours to finish) if one player takes a very long time each turn. However, as a solo game, I find it has perfect length. Additionally, if you’d like it to go faster, you can just use an easier difficulty level and reduce the amount of planning you’ll need to do.

Although I think the theme (terraforming mars) was applied rather superficially, i.e., you could apply the same mechanics to almost anything related to resource management, I don’t really care. That’s because I don’t care about themes, I care about optimization mechanisms.

Why You Should Play This Solo

If you like solving optimization puzzles, managing resources, or watching compound interest grow, Terraforming Mars is the solo game for you. This is the game for those who like to mess around with systems until everything works flawlessly.

If you prefer games that run under 2 hours, don’t require a lot of set up, and provide an almost endless supply of new experiences — Terraforming Mars will fit the bill. As of right now, I have completed 142 games of Terraforming Mars, and I am by far not finished yet.

If you get a kick out of learning from your mistakes — i.e., you gain insight into how to improve your strategies from each loss, Terraforming Mars is a fantastic choice. You will receive immediate and obvious feedback, so you will know exactly which decision(s) led to your defeat.

On the other hand, this game isn’t for everyone. It is a slow game. It is a game of optimization, and the enjoyment of the process of creating the perfect engine is likely to be much greater than the enjoyment of winning the game. So, if you prefer to play games with strong narratives, rich thematic settings, and intense dramatic tension, then this is probably not the game for you. Terraforming Mars is about the beauty of a well-designed engine.

However, if you are wired like me — i.e., spreadsheets seem like home, and you are fluent in optimization terminology — then Terraforming Mars is absolutely perfect.

Rating

Terraforming Mars is a 10/10 game, and the reason for that is the solo experience. The engine-building is elegant and fulfilling. The optimization puzzle is challenging, but fair. The replay value is virtually limitless. And the solo experience creates complete clarity: you either hit your mark, or you didn’t, and you will have a clear understanding of which decisions caused you to fail.

At this point, I am at 142 games of Terraforming Mars, and I am seriously looking for my next 58. At any rate, I have found a new engine configuration every time I’ve played, a new corporation to master, and a new area of optimization to investigate.

If you’ve previously played Terraforming Mars in multiplayer and were unimpressed with the experience — give the solo version a shot. If you’ve never played Terraforming Mars before — start with the solo version. You may find that the most enjoyable way to experience this game is to build your engines completely alone and create the ultimate optimization machine.

View our full list of the 10 best games for solo players

Evelyn

Evelyn’s a retired accountant who swapped spreadsheets for score sheets. She writes sharp, analytical takes on complex strategy games—proof that experience always outplays luck. Don’t underestimate her in a game of Terraforming Mars. You’ll regret it.