The ultimate starship designer,
powered by a deep game simulation...

Cosmoteer is a starship design, simulation, and battle game. Design a fleet of ships by laying out individual rooms and corridors, including cannons, lasers, shields, and thrusters. Battle other starships to earn bounties and use that money to expand your own ship. A dynamic crew and combat simulation makes every design decision important and interesting.

Best-In-Class Starship Designer

Design the greatest starship ever made using a starship designer that is easy-to-learn yet limitlessly flexible.

Build your ship by placing individual modules onto a grid—weapons, defenses, engines, reactors, crew's quarters, and more! Few restrictions and no pre-defined, creativity-limiting hull shapes mean you can create almost any ship you can imagine.

Learn the game systems by watching as your crew scramble to power and operate new modules in real-time as you add them. The Ship Designer is directly integrated into the gameplay—no need to interrupt your flow to tweak your ship or experiment with a new design.

Inspired by professional art programs, the Ship Designer has full support for Undo & Redo, Copy & Paste, rotation, and mirroring, so you can quickly and easily design giant starships. It even has a "blueprint mode" which allows you to plan for the future and design without restriction.

Intelligent Crew Simulation

Every starship is operated by a crew numbering from half-a-dozen to hundreds—sometimes more than a thousand—of individually-simulated people.

A ship's crew is its lifeblood. Crew not only operate its controls, but they also carry supplies such as ammunition and power batteries to weapons and systems. When a weapon wants to shoot, the crew go pick up ammo or batteries at an ammo factory or reactor and bring them to the weapon—all simulated in real-time down to the individual people and supplies.

Crew are pretty smart and act mostly on their own, which is a good thing since there can be so many. Your crew are smart enough to figure out what controls need operating, what systems need ammo or power, and how best to get around your ship. They're even smart enough to avoid routes that are already jammed with other people.

The crew simulation is what makes starship design so interesting, because how fast a cannon can shoot or how long a shield can stay charged depends directly on how quickly crew can deliver ammo or power to it. As a player, you'll have to think carefully about how you design your ship's layout so that it operates at peak efficiency without exposing its more vulnerable (and sometimes explosive!) systems.

Physics That Matter

Every ship is part of a realistic 2D physics simulation. Ships have weight and a center-of-mass depending on their size and shape. Small ships with lots of thrusters are realistically fast and nimble, while large ships with proportionally fewer thrusters are naturally slower and more difficult to maneuver.

The position and orientation of your ship's thrusters affects its movement. Thrusters near its center-of-mass are great at pushing the ship forward, whereas off-center thrusters are effective at rotating the ship. Thrusters pointing forward are needed to decelerate, while thrusters pointing to the sides will let it strafe.

The A.I. will control your ship's thrusters, automatically determining the optimal ignition level for each thruster in order to fly your ship wherever you tell it to go.

Ships can collide and block weapons fire. The shape of a ship determines its collision properties. Weapons must be placed in locations that have good line-of-sight to the enemy, otherwise the ship will block its own shots.

Emergent Combat Model

Weapons obey the laws of the physics simulation. Whether or not a cannon or laser hits an enemy depends not on a roll of the dice but upon the physics of the weapon and its target.

Damage is modeled module-by-module, and each module can be individually targeted & destroyed. There's no big "health bar" for the whole ship—a ship is only "dead" once all of the modules that it needs to function are gone.

Some modules can explode causing collateral damage to the surrounding modules. This means that you'll have to think carefully about where you place your reactors and munitions. Too close to the edge and they'll be exposed to enemy fire; too far and your weapons won't fire fast enough.

Ships can break apart into multiple pieces when their connecting modules are destroyed. Usually this will be a crippling blow, but any piece that has a control room, power, and thrusters can continue to operate independently, potentially remaining a threat to the enemy.

Epic Tactical Strategy

Classic RTS-style controls make the game easy to learn. Simply right-click where you want your ship to fly, or right-click on an enemy to attack it. Advanced controls let you adjust the orientation, distance, and angle of attack.

Target your weapons to focus their fire on the vulnerable parts of enemy ships. Do you take out the weapons first, go for the explosive power core, or eliminate the command-and-control center? Every ship is different, and the right strategy varies greatly.

Command a fleet of ships, outmaneuvering and flanking the enemy to expose its weak side. Specialize your fleet's ships into roles however you see fit.

Starship Painter

The surface of a ship is like an artist's canvas. The Ship Painter is even easier to use than the Ship Designer, requiring no drawing ability to make your ship look great.

Pick a color and texture to customize your ship's basic appearance. If you're not artistically inclined then no need to do more, but otherwise you can...

Add decals to decorate your ship. Every ship has two independently-colored layers of decals. Decals are small shapes, icons, symbols, letters, and numbers that you can stamp on your ship to give it extra visual flourish.

Painting your ship is free and has no effect on gameplay.

Bounty Hunter

You are a bounty hunter, traveling from sector to sector, hunting down renegade enemies and destroying them.

Earn money for every enemy vanquished. Use your income to repair and upgrade your own ship, growing bigger and more powerful with every victory.

Explore a galaxy in search of bigger and more powerful enemies. As your own ship grows in size and power, you will soon be able to defeat even the strongest foes.

Expand your fleet by purchasing additional ships. The galaxy will crumble before your almighty armada!

Creative Mode

Play in a creative sandbox mode if being a bounty hunter isn't your cup of Earl Grey.

Design ships with unlimited funds. The only limit in Creative Mode is your imagination! (And the power of your computer.)

Pit your designs against each other and import designs from other players, competing to be the master designer.

Or just turn on the A.I., sit back, and watch massive fleets annihilate each other! (Great for hosting A.I.-controlled tournaments!)

And more!

Everything you should expect from a great PC game, including customizable controls, windowed and borderless display modes, support for high-resolution displays, no mandatory locked framerates, and dozens of other options to tailor the game to your own preferences.

Attention to accessibility issues wherever possible in order to support gamers of all abilities. Every single control and mouse button can be remapped, the user interface can be made twice as big, and colors that convey meaningful information can be freely changed.

Unobtrusive tutorials that don't interrupt gameplay and are easy to dismiss or turn off altogether. There's no special "tutorial level" you need to play through—the context-sensitive tips are built-in to the main Bounty Hunter mode.

A mods manager makes it easy to install and uninstall mods created by the Cosmoteer community. A powerful modding framework lets mods change literally any part of the game data, opening up a universe of possibilities beyond the base game.

Main Website


Chat (Discord)


  • View media
  • View media
  • View media
  • View media
  • View media
  • View media
Post article RSS Articles

Given the lack of updates for the past couple of months, you'd be forgiven for thinking that I had stopped working on Cosmoteer. Thankfully, you could not be more mistaken!

I've actually been working on one of the biggest new features in the history of Cosmoteer: Multiplayer!

Those of you who have been following Cosmoteer for a really long time probably know that the original prototype versions had support for multiplayer in which players could design ships and battle them with their friends. But I realized that having to support multiplayer was dramatically slowing down the development of Cosmoteer, including development of singleplayer-only features. And so I removed multiplayer support from the game's code, hoping (but not expecting) that one day I would be able to bring it back.

Well, that day has arrived! I am incredibly proud and excited to announce that multiplayer is returning to Cosmoteer!

In this first version, multiplayer is a simple team-versus-team battle of up to 8 players spread across two teams. Each team has a certain amount of money (configured by the host) to spend on a fleet of up to 5 ships per player (or fewer, as configured by the host). Then the game starts and the players control their own ships, attempting to destroy the other team's fleet. The game ends and one team is declared the winner when either the other team's fleet is sufficiently destroyed or the timer runs out.

You can play with anyone on the same LAN (Local Area Network) as you, and you can also play with a friend anywhere else in the world by typing in the host computer's I.P. address. (There is not yet a public online list of games, but I hope to add that soon.)

This is just the beginning! This first version lays the coding foundation for more improvements to come. In the long term, I may add entirely different game modes, such as multiplayer co-op and creative modes. In the near future, I plan to add:

  • A.I. players in multiplayer battles
  • Observers (for streaming tournaments)
  • More than two teams & free-for-all battles
  • Some sort of boundary around the playing area to prevent people from being able to run away indefinitely
  • Limit price per-ship and not just total price per fleet

There's lots more details and plenty of other fixes and improvements in the full changelog.

Technical Implementation

You may be wondering why I've chosen to bring back multiplayer given the fact that I originally removed it because it was slowing down development too much. Wouldn't bringing back multiplayer cause all future development to become a lot slower?

Thankfully, the answer to that is mostly "no", and the reason for that is that I've taken an entirely different approach to implementing the multiplayer code.

The original implementation of the multiplayer code required that every single change in the state of the game (such as a ship firing a weapon, a ship moving a millimeter, a crew person walking a foot, or a bullet hitting an enemy) be synchronized among all players by sending packets over the internet. This was a huge problem for two very important reasons:

  1. In a game as complex as Cosmoteer with potentially dozens of ships and thousands of crew, that's a potentially huge amount data that needs to be transferred over the internet between all the players. We're talking megabytes per second of data for a large battle, which made the game really only playable on LAN or very-high-speed internet connections.
  2. The code for anything that could affect gameplay even in the slightest became way more complicated due to the need to send those aforementioned internet packets. For example, if I wanted a bullet to inflict 1000 damage on an enemy ship, I couldn't just call the TakeDamage(1000) function; I first had to construct a network packet with all the needed information and send it to all other players. This made working on gameplay code far more time-consuming that it would've been without having to send all those packets.

The new multiplayer code uses an entirely different approach that's called "deterministic lockstep". Essentially, this approach requires that two computers running the same version of the game with the same initial battle setup and same player inputs will simulate the game in exactly the same way. (Not even off by a millimeter, or else the butterfly effect will cause bigger and bigger errors until the game desyncs.) There are two big advantages to using deterministic lockstep:

  1. Only player inputs (commands issued to the ship) need to be turned into packets and sent over the internet. Everything else (physics, weapons, damage, etc...) will happen exactly the same way on every computer by virtue of them running completely deterministic game simulations. This saves massively on bandwidth, so much so that Cosmoteer now only uses a few KB of bandwidth per second.
  2. Code that affects gameplay no longer needs to be synchronized using packets sent over the internet, so long as the gameplay code can be written to be 100% deterministic. Writing deterministic gameplay code isn't very hard as long as you know what kinds of things to avoid (primarily code whose outcome could change based on framerate).

There are, however, some important disadvantages to using deterministic lockstep:

  1. The gameplay really does have to be 100% deterministic. 99% deterministic is not good enough. And non-determinism bugs can be very tricky to track down. I have written myself some pretty nice tools for debugging determinism issues, but it still took me several weeks to comb through the whole Cosmoteer codebase and convert everything to be deterministic.
  2. Games that use deterministic lockstep typically have more latency than other types of games. You may notice that when playing multiplayer Cosmoteer (and most RTS games) that there's a small delay after assigning a ship an order and before you see it actually respond. That's because it has to wait for the other computers to receive the order before it can process it. In action games like first-person-shooters, this would be a huge problem, but in slower games like Cosmoteer, it's not a big issue.
  3. Differences in how different CPUs compute floating-point (fractional) numbers can cause an otherwise 100% deterministic simulation to become only 99% deterministic, which due to the butterfly effect will ultimately lead to desyncs. In practice, this means that players running on 64-bit operating systems can't play with players on 32-bit operating systems. (Although there is a mode to force the game into 32-bits so that friends on different operating systems can play with each other.)

While these downsides are significant, none of them are deal-breaking, and are certainly preferable than the problems caused by the original way I implemented the multiplayer code.

All in all, getting multiplayer working again was a pretty huge undertaking -- one that I wasn't even sure I could pull off -- but in the end I think it has proven to be well worth it. And I'm looking forward to playing a ton of Cosmoteer multiplayer as a result!

Cosmoteer 0.12.0 -- Missiles, Fires, and more!

Cosmoteer 0.12.0 -- Missiles, Fires, and more!

News 2 comments

This past Wednesday I released live to the world version 0.12.0 of Cosmoteer, and oh boy was this a big release! It's got new weapons, new defenses, a...

Cosmoteer 0.11.4 - A Universe of Particles!

Cosmoteer 0.11.4 - A Universe of Particles!

News 1 comment

Last week, I released version 0.11.4 of Cosmoteer. Despite only being a minor bump in version number, this release has lots of new stuff! The changelog...

Cosmoteer 0.11.0 -- Fog of War & U.I. Improvements

Cosmoteer 0.11.0 -- Fog of War & U.I. Improvements


Last week I released version 0.11.0 of Cosmoteer. It, and version 0.10.7 before it, add some significant new features and improvements to the game's user...

Cosmoteer 0.11.2

Cosmoteer 0.11.2


Cosmoteer 0.11.2 has been released! It fixes several crash bugs.

Add file RSS Files
Cosmoteer Setup

Cosmoteer Setup

Full Version 8 comments

This is the installer program for Cosmoteer on Windows 7/8/10. Simply download and run. The installer may require internet access if it needs to download...

Better ship mod

Better ship mod

Better ship mod Full Version 1 comment

This mod might be very helpful to you if you like not having to make fire extinguishers, get a full refund when selling stuff, and cheaper repair

Comments  (0 - 10 of 23)

This comment is currently awaiting admin approval, join now to view.


This comment is currently awaiting admin approval, join now to view.


This comment is currently awaiting admin approval, join now to view.


This comment is currently awaiting admin approval, join now to view.


This comment is currently awaiting admin approval, join now to view.


This comment is currently awaiting admin approval, join now to view.


This comment is currently awaiting admin approval, join now to view.


This comment is currently awaiting admin approval, join now to view.


This comment is currently awaiting admin approval, join now to view.


U should make this game for iOS

Reply Good karma Bad karma+1 vote
Post a comment
Sign in or join with:

Only registered members can share their thoughts. So come on! Join the community today (totally free - or sign in with your social account on the right) and join in the conversation.

Follow Report Profile
Send Message
Release date
Game watch
Community Rating



16 votes submitted.

You Say


Ratings closed.

Highest Rated (4 agree) 10/10

An excellent game.

May 14 2017 by Mister_Square

Single Player

Latest tweets from @cosmoteergame

Cosmoteer 0.13.0 is out! It adds the #1 most-requested feature: MULTIPLAYER! Download it and see the full list of c…

Nov 12 2017

The @spacegamejunkie podcast did an episode on Cosmoteer! Give it a listen!

Oct 12 2017

Cosmoteer 0.12.12 fixes a bunch of bugs and makes a lot of balance improvements! Download from

Sep 19 2017

Cosmoteer 0.12.11 adds difficulty levels, enemy fleets, choice of starting ship, and a ton of other improvements!

Sep 11 2017

Cosmoteer 0.12.10 adds ship formations and a ton of other improvements and fixes! Download from

Aug 16 2017

Cosmoteer 0.12.9 fixes a ton of bugs and has a bunch of other improvements. Download from

Jul 26 2017

Cosmoteer 0.12.8 fixes a bunch of bugs and has lots of other improvements! Download from

Jul 16 2017

RT @Lathrix: Second episode of @CosmoteerGame is now out after such a positive reception with the first :D

Jul 12 2017

RT @ScrapManYT: BIGGEST SHIP POSSIBLE! #cosmoteer @CosmoteerGame

Jul 12 2017

Cosmoteer 0.12.7 is out with bug fixes and balance tweaks! Download from

Jul 12 2017

Embed Buttons
Link to Cosmoteer by selecting a button and using the embed code provided more...
Last Update
57 members
You may also like
Barotrauma Futuristic Sim
PULSAR: Lost Colony
PULSAR: Lost Colony Futuristic Sim
Viscera Cleanup Detail
Viscera Cleanup Detail Futuristic Sim
The Babylon Project
The Babylon Project Futuristic Sim
Galactic Crew
Galactic Crew Futuristic Sim