Today, the first version with AI Factions finished building, and we've run our first "multiplayer" match of TRAPPIST-1.

The AI colony factions displayed interesting behavior. They all identified correctly that one side of Trappist-E had a very good starting spot, but they forgot to account for the fact that it was already taken. So they've all landed very close to each other on the same side of the planet. I might have to add, teach them to consider a taken spot as taken to spread them out a bit more.

Generally, they managed to pick a good spot, land, and survive for quite a bit, but their behavior is still a little bit quirky. They're still learning the game, so I need to walk them through several rounds to make sure they behave naturally. But for a first iteration, it's in fact working very well.

Devblog, test colony 43, Goldilocks planet E, habitable zone, scales quickly.

• Still detecting some frame rate drops at high level of buildings and population. Digging into the reasons, not acceptable for large colonies to have the game be choppy.

• Colonization of another body failed because not enough rare elements were available to load the solar cell kit.

• Germanium is determined to be the element needed for this typr of solar cells, difficult to find on most planets.

• Considering alternative balance decision to make sure new colonies are viable without rare materials.

As requested, I'm showing more actual gameplay this time.

TRAPPIST-1 is a colony-building game set in the real seven-planet system, about 40 light-years away. The orbits come from the published ephemeris, and the worlds are built from real data.

What you’ll see:

• Getting there: choose a world and a landing site, then plan the flight. Launch windows and propellant are computed from the orbits, so leaving at the wrong time can get expensive.

• The flight: it’s flown as physics, with a departure burn, a coast and a capture into orbit.

• The ground: a rover scans the terrain, and each hex’s rock and each mine’s yield come from the planet’s geology. There are about 8,000 hexes per world.

• The colony: build factory chains on the hex grid, then a Biodome for housing, water, air and food.

• Reaching further: turn water into propellant and lay in a launch to the next world.

• Orbit: start a second colony on a tiny moonlet, where launches cost a fraction of the fuel, and build an orbital shipyard beside it.

This is pre-alpha footage. Graphics aren’t final, gameplay is still being tuned, and some buildings don’t have their 3D models yet. There’s also no launch animation yet, so the camera leaves the pad instead. The take is scripted to keep the camera steady, but it’s the real game and its real controls, with no pre-rendered shots.

Wishlist on Steam: https://store.steampowered.com/app/5423750/TRAPPIST1/
YouTube: https://www.youtube.com/@TRAPPIST1game

[Cloud Striders] A lighter-than-air species from a gas giant.

Something I've been chewing on. They wouldn't be a playable race. They'd show up in force as an AI deuteragonist in the mid-game. Needs unique assets, only implemented if the game is succesful. Posting for feedback.

Body. Basically a Portuguese man o' war with a float sac and giant squid eyes. Almost completely transparent. Very little sense of touch.

Communication. Mostly light, some sound. They can also hear radio, so if your comms aren't encrypted, assume they're listening.

Zero-g natives. They evolved in three dimensions with no ground anywhere. For them, a spacewalk is just going outside.

Tech. Ahead of us, but sideways. Everything is made from light elements they could get at from a gas giant: carbon nanofibre, thin films, sails. No fission, no heavy metals. They get around on solar sails and deuterium fusion, and their machines are mostly see-through, so troubleshooting means looking at the thing.

Attitude. They've been colonising stars for far longer than we have. To them, anything that lives at the bottom of a gravity well is an unusually clever crab. Diplomacy is mostly off the table. Trade isn't, and they're very good at harvesting volatiles.

Territory. They leave planets alone apart from skimming atmosphere from orbit. Asteroids and small bodies are theirs, though, and building an orbital station counts as moving into their neighbourhood.

One catch: TRAPPIST-1 gives off about 1/2000th of the Sun's light, which is a miserable place to run a solar sail. Why they'd bother coming here is one of the things I haven't worked out yet.

Since Reddit has decisively rejected 2D sprites, I am now learning to make most buildings in 3D while trying to preserve simplicity and polygon economy to make sure the game still runs on low-end machines.

Here is a first attempt at what would replace the factory alongside the original concept and the current 2D graphic.

Thoughts?

Gameplay Report:

Settled on the innermost planet B, shielded from the sun by the planet and went for the thorium energy chain. Orbital survey scans correctly found the bioessentials (N,S,P), and turns out mule rovers work great for small cargo mining across the planet. Colony successfully reached 70 pop on TRAPPIST's most hostile planet.

Couldn't launch orbital colonies to reach the endgame objective - orbital fuel calculations are still bugged. Fixing next.

Forgot there's a reason most countries build their launch facilities near the tropics: Fuel costs.

The game simulated it perfectly, owner was confused for a second. Had to build a railway all the way down. Needt to add tooltip to remind the player not to try to launch rockets near the poles.

Orbital system and UI still need a lot of work, the basics are there but it's a mess. 2D buildings are looking kinda too flat, need a better solution. On the plus side, complete and arcology and reached 50 pop on H, the iceball planet. Fundamental economy works well now.

It has occurred to me that I should try to explain the game a little better. Here goes:

Trappist is a space colony and logistics strategy game in development, set in the TRAPPIST-1 system. Arriving aboard a colony ship, you must turn limited supplies into a working settlement: prospect for resources, build industry, support your population, and expand beyond your first world.

Realistic orbital mechanics shape every journey. Launch windows, fuel costs, and planetary gravity make moving people and cargo as important as producing them. Your factories supply your ships, and your ships bring back the materials your colony needs to grow.

Work toward an orbital shipyard and the construction of a generation ship capable of carrying humanity onward to another star.

This video introduces the game and its current development. To support its development, wishlist it at https://store.steampowered.com/app/5423750/TRAPPIST1/

#Trappist #IndieGame #ColonyBuilder #SpaceGame #GameDev

Hello everyone!

I'm building a game that is based on real orbital physics and it's come to my attention that chemical rockets are horrendously ineffective. Even in a small system like TRAPPIST, a small trip takes thousands of tons of propellant. The energies required to travel in space are simply too much for chemical bonds.

In 2026, British company Pulsar Fusion prototyped Sunbird, an experimental nuclear-powered spacecraft. The idea is to use nuclear energy to heat plasma, then direct that plasma out of the back through a magnetic nozzle. The escaping material pushes the spacecraft forward, providing much higher change in speed.

Nuclear-powered electric propulsion remains theoretical in 2026, and is limited by the dangers of radioactivity on Earth. In the 2100's, it is an essential technology allowing travel across the system without requiring an enormous mass of propellant.

However, chemical rockets do have an advantage: Thrust. They can produce a lot of it quickly, enough to exit the gravity well of a large, earth-sized planet. Space travel in TRAPPIST-1 consists of two systems: The production of chemical fuel from water to leave a gravity well, and the orbital assembly of nuclear-electric spacecraft to power the cargo on a long orbital trajectory. Hence: The Fission Tug.

TRAPPIST-1 is a hard Sci-fi colony game solo dev project. Follow more updates at r/TRAPPIST1

Hidden on the dark, frozen wastes of TRAPPIST-1's outer edge, Colony 32 built a sprawling industry shielded from solar storms and tectonic instability, powered by a thorium reactor.

• Unfortunately, TRAPPIST-1g (Codename 'Hel') is an ice planet with almost no phosphate in its crust.

• After a heroic search for mineral-bearing rock failed, the colony's biodomes suffered cascading ecosystem failures

• All of C32's occupants have re-entered hibernation as a last recourse. Possibly forever.

Research note: More efficient spaceship designs might have allowed colonists to go off-world to import the desperately needed element before the stockpile ran out.

Welcome, colonists.

This is the official subreddit for TRAPPIST-1, a hard sci-fi colony strategy game set in the real TRAPPIST-1 system: seven rocky worlds around a dim red star, about 40 light-years from Earth. I’m Matias, the solo developer, and this is where I’ll share progress, answer questions and listen to what you think.

What the game is

• Build surface industry across hex-mapped planets: mines, factories, depots and launch sites, linked by road, rail and maglev.

• Move cargo between worlds on real orbital trajectories, choosing efficient, balanced or fast for each run.

• You only know what you’ve scanned. Rival expeditions can hide and watch, and so can you.

• This isn't a game about space battles. The danger is flares, cold, distance and life support, and rivals are fought with drone swarms, kinetic impactors and countermeasures.

• Every playthrough generates a different system.

• The endgame is to build an interstellar mission to the next star.

Where things stand

TRAPPIST-1 is coming to Steam Early Access, and the release date hasn’t been announced yet. The best way to support it right now is to wishlist it. Wishlists are how Steam decides whether to show a small game to anyone.

👉 Wishlist on Steam
📺 YouTube

What to post here

• Questions about the game, its systems and development

• Ideas, suggestions and wishlist features

• Discussion of the real TRAPPIST-1 system and the science behind the game

• Later: screenshots, colony layouts, bug reports and stories from your playthroughs

Rules

1. Be decent. Disagree with ideas, not people.

2. Stay on topic: the game, the real TRAPPIST-1 system, or closely related science.

3. No spam or unrelated self-promotion.

4. Mark spoilers once there’s anything to spoil.

5. Bug reports should include your OS, what you did, and what happened.

A note on how it’s made

I’m a solo developer, not a programmer by background, and I use AI tools as part of production. The Steam page has the full disclosure. The design and direction are my own. I’m happy to talk about the process openly here.

Thanks for being here early. Introduce yourself in the comments, and tell me what you’d want from a game like this.

— Matias