Thrive

Every evolution game sells the same fantasy: one cell today, a spacefaring species tomorrow. Most of them treat biology as a costume rack, where body parts are cosmetic swaps with a stat bonus attached. Thrive, an open-source evolution simulator from Revolutionary Games Studio, starts from the opposite premise. The player begins as LUCA, the Last Universal Common Ancestor, the first cell on an alien planet. The opening problem is chemical before it is strategic: how does this cell gather enough compounds to survive and reproduce?

The project has been in Steam Early Access since November 26, 2021, and that date shapes how the whole package should be judged. The Microbe Stage is complete. The Multicellular Stage is in progress with limited gameplay. Every stage after that exists only as a prototype. The long-term goal of taking a species from cell to space is a declared ambition. It is not something a buyer can play today, and buyers should price that in.

What has shipped is substantial:

• a cell editor with a broad part list
• distinct survival strategies
• biomes that range from deep-sea hydrothermal vents to icy surfaces
• planet-scale disruptions such as asteroid impacts and ice ages
• rival species that evolve alongside the player in a background simulation

The game is built with Godot and C#, and it runs on Windows, macOS and Linux.

Its market position is unusual. Thrive is a science-inspired simulation with an open-source pedigree and a low price on Steam. That places it closer to a community-built science toy than to a commercial product chasing a launch window.

Steam user reviews are broadly positive. The praise centres on:

• the cell-to-space concept
• the depth of the editor
• the evolving rivals
• the price
• the developers’ steady stream of updates

The recurring caveat matches what the roadmap already admits: most of the promised game does not exist yet. What does exist is a focused, systems-driven survival game about being very small in a hostile ocean.

• A LUCA starting point: The campaign opens with the first cell on an alien planet. The species’ whole history is built from that single origin.
• Cell editor with a broad part list: Mitochondria, chloroplasts, flagella, and flexible or armored membranes are among the building blocks. Each one changes how the cell gathers compounds, moves, hunts or defends itself.
• Metabolic paths: Photosynthesis, chemosynthesis and predation are separate ways to make a living, and each pulls the design in a different direction.
• Biome range: Environments span from deep-sea hydrothermal vents to icy surfaces, so the same species can face very different survival conditions.
• Planetary events: Asteroid impacts and ice ages change the conditions a species must survive. A build that works today may fail tomorrow.
• Evolving rivals: Competing populations are simulated in the background and evolve too. Population graphs track how the ecosystem shifts over time.
• Tutorial and freebuild sandbox: There is a guided entry point, plus a no-pressure mode for testing designs.
• Steam extras: Steam Workshop support, achievements and cloud saves.

The Gameplay Loop

Thrive runs on a simple loop. First, survive in the world. Then, redesign in the editor. In the world, the cell gathers compounds, avoids threats and reproduces. In the editor, the species mutates and adapts.

A loop like this works only if the two halves feed each other, and Thrive’s part list is designed so they do. A chloroplast commits the species to one way of feeding. A flagellum commits it to movement. An armored membrane commits it to surviving contact. Every editor decision sends the player back into the world with a new set of problems.

That is the right shape for a game about adaptation. Nobody “solves” a build in Thrive. A design only fits current conditions for a while, until something changes.

The Cell Editor

The part count is modest for a creature builder. The number matters less than how tightly the parts connect to the rules of the world. Each part maps onto a core action: gathering, moving, hunting or defending.

Naming the parts after real biology does useful work. Mitochondria and chloroplasts carry the weight of their real-world roles. Players with any memory of school biology get an intuition for what a part probably does before they place it.

The choice between flexible and armored membranes shows the design philosophy most clearly. It is a trade-off rather than an upgrade. A protective shell and a pliable body point the species toward different lives.

That coupling is also where the learning curve comes from, and Steam users name the curve as a sticking point. Because every part has consequences, a poorly reasoned cell does not just perform a bit worse. It struggles to survive. Thrive asks players to think like a designer of organisms, and that is a steeper request than “pick the bigger number.”

Ways to Eat

The split between photosynthesis, chemosynthesis and predation is the game’s clearest structural idea. These are not difficulty settings with different skins. Each one is a different relationship with the environment:

• Predation pushes the game toward pursuit and combat, where flagella and defenses matter most.
• Photosynthesis and chemosynthesis shift the emphasis to where a species lives and what that place supplies.
• Hydrothermal vents give chemosynthesis an obvious home. Pairing a real deep-sea food source with the biome list is the kind of grounded detail that earns Thrive its science-inspired label.

These paths give the campaign real replay value. A later run as a predator, after a run as a photosynthesizer, should feel like a different game rather than a reshuffle of the same one.

An Ecosystem That Pushes Back

Rival populations are simulated in the background and evolve alongside the player. Asteroid impacts and ice ages rewrite the conditions everyone is competing under. Together, these keep the world a moving target. A design tuned for one set of conditions can become a liability when the climate shifts. The game punishes complacency in the same way natural selection does.

The population graphs are the tool that makes all of this readable. They turn an invisible simulation into data the player can interpret. A rival’s rise or a species’ collapse becomes a curve with a cause behind it.

There is a cost to this approach. When the simulation runs off-screen, its results often arrive as numbers rather than as dramatic events. Systems-minded players will read those graphs like a field researcher’s notebook. Players who want ecological drama to happen in front of them may find the presentation dry.

Onboarding and Friction

A tutorial covers the basics. The more important onboarding tool is the freebuild sandbox. It lets players experiment in the editor without the threat of extinction, which is exactly the safety net a dense, consequence-heavy editor needs. Players who bounce off the campaign’s difficulty should start there.

Steam users also mention rough edges. In a game that has been in Early Access for years and is still building its second stage, that is expected rather than damning. It still deserves a clear warning.

The Roadmap Question

This is the decisive issue. Only the Microbe Stage is complete, the Multicellular Stage has limited gameplay, and the later stages are prototypes. The cell-to-space promise is the hook in every description of Thrive, and it is the part the game delivers least.

The developers’ record of steady updates, which Steam users praise, earns some confidence in the long arc. Steady progress is still not a completion date.

We judge Thrive on what exists. On that basis, the Microbe Stage is a self-contained, replayable survival sim. Steam Workshop support helps stretch its life while the later stages mature. Anyone buying specifically for the full evolutionary journey will be buying a promise.

Thrive’s presentation has a harder job than most games: it has to make microscopic biology readable at a glance. The editor carries most of that burden. With a broad part list, each affecting gathering, movement, hunting or defense, the interface has to communicate trade-offs clearly, or the learning curve turns into guesswork.

The population graphs are the other key screen. They reflect a deliberate choice to favour information over spectacle, which suits the game’s scientific framing better than cinematic flourish would. The biome range, from dark hydrothermal vents to icy surfaces, gives the setting a wide visual palette in principle. Those environments do real design work by signalling which survival strategy belongs where.

On performance, a microbe-scale scene should not demand much from the graphics hardware. The heavier load is the background simulation of rival species, which grows with the size of the ecosystem rather than with visual detail.

Godot and C# give the project a cross-platform foundation across Windows, macOS and Linux. The rough edges Steam users mention fit a project still mid-development, so expect some unevenness rather than release-grade polish.

Steam is the only storefront listed, and the release covers the major desktop systems:

• OS coverage: Native Windows, macOS and Linux support puts the full Microbe Stage on every major PC platform. That matters most to Linux and Mac players, who often get ports late or not at all.
• Input: A part-heavy editor and graph-driven feedback point to mouse and keyboard as the natural control scheme. No controller or touch version is listed, so players who want couch play should look elsewhere.
• Steam integration: Workshop support opens the door to community content. Achievements add structure to a sandbox-leaning game. Cloud saves make it easier to keep long evolutionary runs going across machines.
• Pricing: At $4.99, the game is inexpensive for an open-source project. Buying on Steam is as much a way to back a long-horizon project as it is a purchase of finished content.

Thrive handles its hardest part well. Its complete Microbe Stage treats survival as a chemistry problem, links every editor choice to a concrete behaviour, and places the species in an ecosystem that keeps changing underneath it. The survival strategies give the Microbe Stage real replay value. The freebuild sandbox softens a learning curve that is real.

The weakness is scope, and it is a large one. A game sold on the promise of going from cell to space currently delivers the cell, part of the next step, and prototypes beyond that.

We recommend Thrive at $4.99 to players who will value the Microbe Stage on its own terms and treat everything after it as a bonus still in progress. Anyone waiting for the full evolutionary journey should add it to their wishlist and check back.