Apr 14, 2026

Two New Demos: Realtime Tanks & Turn-based Cards

One Colyseus server, a pile of client engines. Pick a style, clone a repo, start hacking.

By Endel Dreyer

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Two new open-source demos, built to stress-test Colyseus’s “one server, any engine” promise.

Each one ships a single TypeScript server plus a pile of client implementations — Unity, Godot, GameMaker, Defold, MonoGame, Construct 3, Three.js, PlayCanvas, React, and Haxe — all talking to the same rooms.

Pick a style, clone a repo, start hacking.

Realtime Tanks

Team-based tank combat for up to 12 players: drive with WASD, aim with the mouse, grab repair / damage / shield power-ups, and shoot your way to 10 points before the other team does.

Engines: Unity, Godot, GameMaker, Defold, MonoGame, Construct 3, Three.js, PlayCanvas, Haxe/Heaps.

Under the hood:

• Fully authoritative server — movement, shooting, damage, and pickups all resolve server-side.
• Spatial clustering keeps collision checks cheap as rooms fill up.
• MapSchema for tanks / bullets / pickables, ArraySchema for teams.

Play it live at colyseus.io/realtime-tanks-demo — every web client in the repo plays against the same server, so a Three.js tank really is in the same match as a Godot one. Source: colyseus/realtime-tanks-demo.

Turn-based Cards

A multiplayer card game in the shape of UNO: match by color or number, drop action cards, stack +2s and +4s, win by emptying your hand. Rooms come pre-populated with bots so nobody stares at an empty lobby — bots step out as humans join and step back in when they leave.

Engines: Unity, Godot, GameMaker, Defold, React + React Three Fiber, Three.js, Haxe/Heaps.

Under the hood:

• Authoritative card validation — the server owns the deck, clients only request plays.
• Hidden information via StateView: you see your own hand; everyone else is just a handCount.
• Turn deadlines auto-resolve so one AFK player can’t stall the table.
• Seamless human ↔ bot swapping and reconnection — rooms survive churn without resetting.

Source: colyseus/turnbased-cards-demo. (“UNO” is a Mattel trademark; this is an independent educational project, not affiliated with Mattel. Card art from 4Colour Cards by VerzatileDev.)

One server, any engine

Both repos have the same shape: one server/ with the Colyseus room, and a sibling folder per client. No per-engine server, no translation layer, no duplicated game logic — every client speaks the same schema over the same WebSocket.

Both are MIT-licensed and built to be forked. Pick the one closest to your game, delete the clients you don’t need, and you’ve got a head start. Questions or war stories — find us on Discord or GitHub.