Kosmaris is a browser-based multiplayer space strategy game. No download, no plug-in, no install — you register a free account, claim a homeworld, and start playing in any modern browser. This post is the introduction: what the game is, what you'll actually be doing, and what we're building toward.
One shared galaxy
Kosmaris takes place in a single persistent galaxy shared by every player. It isn't a private instance or a matchmade round — it's one spiral-shaped map, laid out in real coordinates, that keeps running whether you're logged in or not. Every planet on the map has a live owner. Every fleet in transit is actually travelling right now, at a travel time computed from real distance. Log off for a day and the galaxy hasn't paused for you — your mines have kept producing, and your rivals have kept moving.
Build an economy
You start with one homeworld and a handful of resources. From there, the core loop is economic: mines extract the raw materials that fuel everything else, a workforce staffs your buildings to boost their output, and upgrade queues turn accumulated resources into more capacity. Colonizing new worlds — across different planetary environments — expands how much you can produce at once. Every planet you hold is another engine to manage and optimise.
Research, then build fleets
A technology tree gates ships and capabilities behind research. Early unlocks open the door to more advanced ones, so the order you choose to research in is a real strategic decision, not busywork. Once you have a shipyard and some hulls in your roster, you can send fleets out on missions — moving cargo between your own planets, scouting or spying on someone else's, staking a claim on an empty world, or attacking a rival outright. Every mission has a real flight time and a real outcome.
Combat and consequence
When fleets meet in battle, Kosmaris produces a full after-action report — what each side brought, what was lost, what survived, and what was looted or destroyed. There's no hidden dice roll to second-guess: you can see exactly what happened and adjust your fleet composition for next time. Winning is about building and deploying a better fleet, not getting lucky.
Not going it alone
You don't have to play solo. Players can band together, coordinate strategy, and support each other's expansion and defence. A galaxy-wide leaderboard tracks everyone's standing as it develops, so your progress is measured against the whole shared population, not just your own numbers.
Why we're writing this blog
Kosmaris is under active development, and this dev blog is where we'll be posting what changes and why — new mechanics, balance adjustments, and fixes, as they ship. If you want the full breakdown of how any given system works, the in-game Game Guide covers it in detail. If you just want to see the galaxy for yourself, the fastest way is to play for free and claim a homeworld.
Welcome to Kosmaris. We're glad you're here.