Microbe Stage

This article describes design decisions that will be rediscussed before their implementation in the future, and as such are not final.


Previous stage: No earlier stages.
Next stage: Multicellular stage

The Microbe Stage is the first stage of the game. You start off as a simple cell and must survive to collect enough nutrients to reproduce. Every time you reproduce, you can evolve your cell in the Microbe Editor. The stage ends when two cells of your species bind together.


The Microbe Stage can be seen as having two types of gameplay: Environmental gameplay, and editor gameplay. Environmental is when the player is controlling their cell, hunting for nutrients, and competing to survive; editor gameplay is when the player is in the editor designing their microbe to adapt to the competition and environment.

Environmental gameplay is based on:

  • Exploration
  • Resource gathering
  • Interaction with other microbes

Editor gameplay is based on:

  • Strategic evolutions to your microbe
  • AI microbes that evolve simultaneously to you (Auto-Evo)


  • Being the first stage, there is no transition into the Microbe Stage.
  • To progress into the Multicellular Stage, the player will need to bind with another member of their species to form a multicellular colony. This is possible with the evolution of Adhesion Proteins.


Status: Work in progress

  • The environment is the gameplay space of the microbe. The environment is comprised of abiotic (non-living) and biotic (living) components.

Abiotic Environment Components

  • Water currents. A fluid dynamics simulation will have streams of liquid (usually water) current constantly flowing through the environment.
  • Compound clouds. Procedurally generated clouds of compounds (coded by colour) will appear in the environment.
  • Environmental conditions. Invisible noise maps of light, temperature, salinity, acidity, pressure, and other environment conditions will exist in the environment.
  • Surfaces. Procedurally generated solid barriers that block movement and currents, representing rock formations underwater.

Biotic Environment Components

  • Microbes. The environment will start with a set of microbes (or possibly even just an original species), and then Auto-Evo will evolve these into many species over time.
  • Bacteria. Procedurally generated to populate the environment (coded by colour and shape).
  • Organic Molecules. Large free floating molecules and bits of organisms will be present in the environment. This includes strands/clumps of DNA, proteins, bubbles of membrane/fats, and chains of sugars. They require special adaptations to digest. If the player absorbs them and digests them, they will grant an increased amount of compounds than a cloud. Absorbing the DNA also has a chance to unlock a new organelle for use in the editor.

Environment Layers

  • Foreground. Will contain faint visual effects for aesthetics.
  • Midground. The layer that contains the player and the other environment components.
  • Background. The parallax set of layers behind the player that is for aesthetic purposes. Contains the background images, particle effects, etc.


Main Article: Microbe Biomes

  • The environment is split between multiple Biomes. The biome you're in determines the appearance of the environment and the presence and abundance of the different biotic and abiotic components.
  • Other biomes cannot be reached via in-game travel. Instead the player will have to choose which biome to spawn in when they leave the editor.
  • There are certain restrictions on what biomes can be found adjacent to other biomes.


  • Compounds can be thought of being like resource gathering from other games.
  • The player's microbe and other microbes and bacteria need certain compounds to survive. Compounds that a microbe or bacteria needs to survive are often called nutrients. A compound might be a nutrient for one species but not for another.
  • Compounds are automatically absorbed by microbes by swimming through them, if the microbe has space to store it. They are stored in the cytoplasm or in vacuoles.
  • Clouds move with the currents, gradually diluting.
  • Compounds can be found throughout the environment in several different forms:
    • Free floating (compound clouds). These are coloured by the type of compound they are.
    • Concentrated in certain areas (heat/light spots).
    • Contained within other microbes/bacteria (storage or as part of their organelles).
  • Agents also appear in the environment in the form of coloured clouds (coloured by type). Agent colours are more nuanced and difficult to decipher. More details here: Agents.
  • Compounds enter the environment from several sources:
    • Bacteria. May eject certain compounds as waste or drop them upon death.
    • Microbes. May eject some as waste or drop them upon death.
    • Natural sources. Volcanic vents, limestone, etc.
  • The player can gather compounds from any of these sources.
  • Energy comes in the form of ATP, which cells create from their compounds. ATP is for the most part treated as a compound.
  • Cells release unnecessary compounds as waste.
  • Absorption and ejection of compounds happens passively. There is a limit to the rate that compounds can be absorbed/ejected in a given moment, and that is based off of the surface area of the cell.


Status: Work in progress

  • Because of the size of the organisms in this stage, they will be heavily affected by fluid dynamics.
  • Pseudopodia (Ameboid movement) will be less effective in stronger currents, in which case movement organelles would be necessary.
  • The player will have to navigate the currents and can use them to their advantage.
  • The speed of the cell and the turning ability will depend on the organelles.
  • Heavier cells will be harder to move. Weight is determined by size, organelles, stored compounds, etc.
  • The cell will face the direction that your cursor is in.


Status: Work in progress

  • Microbes have a set of possible changes they can make each time they enter the editor. These are referred to as mutations. Some mutations are the placement or modification of internal cell parts, called organelles.
  • Organelles are internal machinery, like organs, which allow a cell to perform certain abilities. The player starts with only DNA and a membrane, neither of which technically count as organelles. They can acquire organelles as the game goes on. Organelles are required for a cell to function properly and are crucial for survival.
  • Organelles can be upgraded. Organelle upgrading will not be as good as organelle obtaining, pushing upgrading back to mid-game.
  • New organelles can be unlocked through two ways:
    • Endocytosis - Player unlocks an organelle by engulfing a bacteria.
      • There has to be enough free cytoplasm in the cell for an organelle to be assimilated.
      • An assimilated organelle is unlocked and also has a copy placed in the cell.
    • Organelle Cross-grades/Upgrades - Player upgrades an organelle into a different one (E.g. Cilia to Flagellum).
      • Lamellipodia, pilus, cell wall, agent vacuole
  • Organelles will slowly drift around their placement point in a cell for visual appeal
  • The membrane will distort based on the microbe's interactions with the environment (e.g. Engulfment and movement)
  • A player can turn an organelle's function off from the organelle priorities panel. A turned off organelle will either be darkened or dimmed in colour.
  • For more on organelles, see here.
  • For a list of all organelles check here.


  • Combat's main purpose is to kill another microbe to obtain the compounds it holds.
  • Three main forms of combat:
    • Agents - Can damage or inhibit organelle/behaviour. Can damage attacker as well.
    • Predatory Pili - Pili rupture a cell's membrane, but can also act as agent secretors. Pressing a hotkey will make the pilus extend/activate. Cell walls are more resistant to pili.
    • Engulfing - The traditional form of combat available to most cells. A microbe can usually engulf a microbe or bacteria smaller than itself, provided he has an engulfing edge. Once ingested, a foreign microbe or bacteria is rapidly digested inside.

Health and Death

  • There is no single metric for health for microbes. ATP is most analogous to health.
  • If a microbe bursts, it is considered dead. There are multiple ways this can happen.
  • When organelles are damaged enough, the membrane cannot control osmosis and the cell dies by osmolysis (water explosion). Cells will initially swell to indicate this as a warning.

Organelle Health

  • Each organelle will have its own health meter, but these will be hidden to the player.


  • The cell membrane is assumed to be constantly undergoing osmoregulation passively (using pumps to balance water inside and outside of the cell). Osmoregulation is necessary for the cell to not fill with water, burst, and die.
  • This means that the cell is constantly using a baseline of ATP to keep itself alive. This is why blank cytoplasm hexes still increase ATP consumption.
  • When a cell runs out of ATP, osmoregulation will fail and the membrane will burst. This type of death is known as osmolysis.
  • Highly upgraded cell walls can prevent osmolysis.

Membrane Health

  • A cell will die if its membrane is broken in any way. The membrane has a hidden health meter like all organelles, but if its health reaches zero the cell dies automatically.
  • The membrane cannot be turned off, and consumes no ATP (cytoplasm consumes ATP to represent the ion pumps).
  • Two ways membrane health can be damaged:
    • Agents - Kinase will gradually damage membrane over time.
    • Pili - Can rupture a membrane.


  • A cell can die from being engulfed by a larger cell.
  • A cell can use pili or agents from inside a cell to escape.


  • Upon death, a microbe will release its stored compounds and potentially some of its organelles intact into the environment. Organelles require engulfment to be absorbed, unless an agent breaks them down first.
  • External organelles and periphery organelles collapse immediately along with the membrane. Neither release any compounds into the environment.
  • The nucleus has a small chance of dropping on death. Consuming a nucleus grants compounds and an additional 25 mutation points in the next editor session (doesn't stack).
  • If the player cell dies, the camera freezes in place for a few moments to show how they died, then fades to black. It then fades back in focused on a new cell of the player’s species in the same biome. This cell has low compound stores.
  • If no members of the player’s species are available in the biome, the player is randomly assigned a new individual from another biome. If there are no other members of their species at all, they’ve gone extinct and lose the game.
  • The player sees a brief game over screen (with no sound, explaining that their species has gone extinct), before being sent back to the title screen.


Status: Work in progress

  • An NPC is any in-game entity which can think for itself. There are two main NPC types: eukaryotes and prokaryotes.
  • AI species evolve via Auto-Evo. This evolution takes place while the player is in the editor.
  • Different modes of AI (predatory, plantlike, prey-like possibly).
  • Surviving, seeking out necessary compounds and feeding on them.
  • Killing other microbes (predator mode), this involves using agent vacuoles effectively.
  • Fleeing from predators (prey-like mode, and possibly predators from larger predators)


  • Scientifically, a eukaryote is any cell which contains a nucleus. These types of cells are referred to in Thrive as ‘microbes’, while prokaryotes (which contain no nucleus) are referred to as ‘bacteria’.


  • Bacteria do not evolve, but do reproduce. All bacteria are membrane-enclosed blobs much smaller than eukaryotes.
  • Bacteria can be engulfed by microbes. They grant compounds and a small chance to unlock organelles (process known as endocytosis). The organelle unlocked depends on the bacteria.
  • Four types of bacteria:
    • Cyanobacteria - Photosynthesize and respire.
    • Thermophilic bacteria - Thermosynthesize and respire.
    • Bioluminescent bacteria - Respire and produce light with ATP.
    • Respiring bacteria - Respire.
  • Each type of bacteria has a version with flagella, and one without.
  • Presence varies by biome.
  • Prokaryotes have simple, unchanging AI. Immobile bacteria are unlikely to have any agency at all.
  • More details here: Bacteria.


  • Microbes will compete with one another for resources.
  • They can attack and kill one another or flee.
  • They can also form co-operative colonies and assist each other.


Status: Implemented

  • Only possible reproduction is asexual.
  • Reproduction for microbes is a gradual and incremental process.
  • While a microbe is undamaged, it will slowly use its stored compounds to grow its organelles. It will grow only one organelle at a time.
  • If at any point during this process an organelle takes damage, it will stop the growth of its organelles and may even shrink one of its organelles that had grown to refund the compounds and heal the damage. Reproduction only resumes when all damage is healed.
  • Once an organelle grows to double its normal size, it splits in half. The cell repeats this process until every organelle has split except the nucleus.
  • When all organelles have doubled, the reproduction button pops onto the screen. Clicking the button will show an animation of the enlarged nucleus splitting, and then take the player to the Microbe Editor.
  • After exiting the editor, the cell splits in two with each daughter getting one copy of the organelles. All other microbes of the player species in that biome will be changed to match the mutations.
  • If the two daughter cells have no ability to store all of the compounds, the remainder is released into the environment as compound clouds.

Microbe Editor

Status: Work in progress

  • Only available editor in this stage is the Microbe Editor.
  • It is entered as mentioned above.
  • Each editor session grants a limited number of Mutation Points (based on difficulty). 100 MP by default. Each possible change costs a certain number of MP.
  • The player can add/edit/remove organelles to their cell or change it's shape, size, or structure.
  • For more detail see Microbe Editor.


  • Technically, symbiosis refers to relationships between species that are either positive or negative, but for Thrive by symbiosis we mainly reference beneficial symbiosis.
  • Symbiosis can develop naturally or artificially through binding agents.
  • At first, colonies will be rare or nonexistent. Eventually, they will start to form using signal and binding agents. Colonies allow constituent cells to specialize. The game environment should be weighted towards incentivizing colonies near the end of the stage.


  • Only single-species colonies can form.
  • It’s possible it may use a bitmask system similar to agent resistance.
  • Cells can release a binding agent which will make them attach. They will stay attached unless one cell makes a strong motion to swim away from the other. Colonies will also need signal agents to prevent constituent cells from breaking off.

Emergent Symbiosis

  • Cells may be able to work together to benefit each other.


  • Disasters can affect 1 or more biomes.

Mass Extinctions

  • Rare even in high difficulty.
  • Mass extinctions never happen concurrently with each other or natural disasters.

Other Disasters

  • Asteroid Impact – All biomes become much darker (atmospheric dust), reducing light spots. One non-player biome is randomly chosen to have most of its inhabitants killed off.
  • Snowball Earth – All biomes become much colder, reducing heat spots. Water currents also slow in many places. Ice appears as white floating shapes.

Natural Disasters

  • Natural disasters are much less violent than extinction events, but are more frequent. They affect small numbers of biomes, often as little as one. Their effects plug into the CPA simulation just as extinctions would, but generally don’t have as big an effect.

Natural disasters never happen concurrently with each other or mass extinctions.

  • Volcanic Eruption – Similar to an asteroid impact, but less widespread with less drastic effects. A few adjacent biomes become slightly darker and hotter.
  • Earthquake – The player’s view shakes for ten seconds and water currents change direction in one biome.
  • Virus – One species in a biome is chosen at random to be attacked by a virus. A virus may affect the function of one or more organelles, reducing their efficiency, sometimes heavily. If the player encounters or becomes an infected individual, the affected organelle will glow red and the entire microbe will have a slight red glow.

User Interface

Main Article: Microbe Stage GUI

The interface and controls of the stage.

  • UI is based on a minimalist design
  • In the bottom right, it shows the players compound stores.
  • In the bottom left, there are six buttons.
  • One has a question mark, and is the Help button.
  • Next to that on the right is the Save button.
  • Below that there is the Load button.
  • Clicking the button right in the very corner will hide this part of the interface.
  • In the top left, there is a display of the player's health.
  • In the top right, there is the button for the main menu.

Status: Implemented

Game Screens

Main Article: Game Screens

What is displayed to the player in each section of the game and how to travel between them.


Main Article: Microbe Progression

The different abilities and mechanics available at different stages of the game, and how to win.

Simulation Specifics.

Main Article: Game Features

The nitty-gritty of the game world and its simulated aspects. The different systems for simulating the microbe stage can be found in the main page linked above.


Main Article: Microbe Visuals

Over the course of the Microbe Stage, the camera is locked in a top-down view, although it is in 3D. It will be styled as if the player is looking through a microscope, although it will be more colourful than that.


Main Article: Microbe Audio

What the game sounds like.


Main Article: Microbe Miscellaneous

Things not covered elsewhere.

Related threads


Main Article: Microbe Appendices

Lists of assets and game elements.

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