An AI-driven open-world space RPG where every alien is alive, every planet is unique, and the galaxy keeps moving without you.
Built in Unity with C#. Powered by LLMs, ML-Agents, and a community of open-source creators. Hosted under PlayPath by SJA Pathway — a free, open game development platform.
📋 Track development: Kanban Board (Issues view) · Project Board (Kanban columns) · All Epics
NEXUS pushes AI integration further than anything in the genre. A galaxy where:
- 🧠 LLM-driven NPCs — every alien you meet is backed by an LLM agent with persistent memory across sessions
- 🪐 AI-procedural galaxy — 10,000+ star systems with planets, biomes, lore, and atmospheres generated on demand
- 🎭 AI Game Master — an orchestrator that improvises quests, world events, and tension curves around your playstyle
- 🦎 ML-Agents wildlife — alien fauna trained with reinforcement learning, evolving across generations
- 🎵 Adaptive AI music — per-planet themes generated and remixed on the fly
- 🎙️ Voice with aliens — STT (Whisper) + TTS (ElevenLabs) so you literally talk to NPCs
- 🌐 Persistent shared universe — Photon-networked, civilizations rise and fall while you're offline
Project location: projects/nexus-sentient-galaxy/
You begin as a lone pilot in a procedurally-generated galaxy. From there the game unfolds along six pillars — each backed by a dedicated development epic on the Kanban board.
Pilot a fully customizable spaceship through 10,000+ star systems with 6DoF Newtonian flight. Charge an FTL warp drive to jump through trade lanes — where pirates may patrol. Land on planets with seamless atmospheric entry, walk surfaces shaped by noise-based heightmaps, scan one of six biomes (lava, ice, ocean, jungle, desert, gas giant), and uncover AI-generated lore written for that world alone.
Build your ship from modular hardpoints — lasers, missiles, railguns, shields, engines. Enemy ships use Utility-AI tactics (aggressive, flee, ambush) and coordinate as squads. Damage is positional: target specific subsystems to disable rather than destroy. Cripple a hostile vessel, board it, and fight its crew in interior FPS combat — then add it to your fleet.
Every alien is a real LLM agent with persistent memory across sessions. Speak in text or with your voice via Whisper STT — they reply with ElevenLabs TTS. They remember the deal you struck three sessions ago, the faction leader you betrayed, the rumor you spread. They keep daily schedules, hold grudges, gossip with each other in the background. Build reputation with factions; their tone shifts as you do. Learn alien languages word by word as you play.
Alien wildlife is trained with Unity ML-Agents reinforcement learning. Herbivores forage and flock; predators stalk and ambush. Populations rise and fall on their own — a real ecosystem. Tame creatures, breed them, and watch their DNA drift across generations every time you return to a planet.
An AI Game Master orchestrates the galaxy. It watches your playstyle, reads narrative tension curves, and spawns dynamic events — wars, plagues, discoveries — and proposes quests fitted to your archetype. Choices ripple: kill a faction leader and the economy and diplomacy actually shift. A Codex auto-writes itself with everything you witness, so your playthrough is its own book.
Photon-networked multiplayer with proximity voice chat. The universe is persistent and shared — civilizations evolve while you're offline. Trade in a server-authoritative marketplace, form guilds and fleets with shared treasuries and quests.
Every line above maps to issues on the Kanban backlog — filter by
epic:galaxy-gen,epic:ship-combat,epic:ai-npc,epic:ecosystem-ml,epic:ai-gm, orepic:multiplayer.
100 issues across 10 epics — filter by epic label:
epic:foundation · epic:galaxy-gen · epic:ai-npc · epic:ai-gm · epic:ship-combat · epic:ecosystem-ml · epic:multiplayer · epic:ui-ux · epic:audio · epic:polish-ship
| Layer | Technology | Notes |
|---|---|---|
| Game Engine | Unity 2022.3 LTS (URP) | 2D/3D game engine, supports C# |
| Scripting | C# | Logic and game mechanics |
| Cloud Storage | Firebase / PlayFab | Free cloud storage & player data |
| Multiplayer | Photon Fusion / PUN 2 / Mirror | Free networking for multiplayer games |
| LLM Providers | Anthropic / OpenAI | NPC dialogue, AI Game Master, lore gen |
| ML / RL | Unity ML-Agents | Trained alien wildlife and ecosystems |
| Voice (STT/TTS) | Whisper / ElevenLabs | Voice chat with NPCs |
| AI Music | Suno / Stable Audio | Per-planet adaptive themes |
| Audio Middleware | FMOD / Wwise | Adaptive soundtrack and mixer snapshots |
| Design / Art | Blender / GIMP | Free 3D modeling and graphics tools |
| Version Control | GitHub | Free public repositories |
- Fork this repository.
- Clone your fork:
git clone https://github.com/yourusername/playpath.git cd playpath - Open the project in Unity Hub (Unity 2022.3 LTS).
- Open the scene in
Assets/Scenes/Main.unity. - Run locally using the Unity editor or build for PC / WebGL / Mac / iOS / Android.
- 🌱 Beginners with some experience in Unity or C# are welcome.
- 🧩 Pick an issue tagged with an
epic:*label that interests you, comment to claim it, and open a PR. - 💬 Communicate via our Discord or GitHub discussions.
- 🔍 Follow Unity best practices and keep assets organized in
Assets/_Nexus/{Art,Audio,Code,Prefabs,Scenes,...}.
- Push to
main→ GitHub repository serves as version control. - Unity games can be deployed for free to:
- Itch.io
- PlayFab / Firebase for backend support
- WebGL builds hosted on GitHub Pages
NEXUS development is structured as 10 epics, 100 issues. Phases are guidance, not gates — work happens in parallel.
| Phase | Epic | Focus |
|---|---|---|
| 1 | epic:foundation |
Unity project, save/load, input, services, addressables |
| 2 | epic:galaxy-gen |
Procedural galaxy, planets, biomes, atmospheres, AI lore |
| 3 | epic:ship-combat |
Ship building, 6DoF flight, FTL, weapons, enemy AI, boarding |
| 4 | epic:ai-npc |
LLM NPCs with memory, factions, alien language, moderation |
| 5 | epic:ecosystem-ml |
ML-Agents wildlife, food chains, evolution, taming, bestiary |
| 6 | epic:ai-gm |
AI Game Master, dynamic quests, world events, codex |
| 7 | epic:ui-ux |
Holographic HUD, star map, photo mode, accessibility, i18n |
| 8 | epic:audio |
FMOD/Wwise, adaptive music, AI voices, STT, mixer snapshots |
| 9 | epic:multiplayer |
Photon, persistent universe, guilds, marketplace, voice chat |
| 10 | epic:polish-ship |
CI/CD, optimization, alpha test, trailer, store pages, v1.0 |
- All art and assets used should be free or open-source.
- Builds should support both PC and WebGL where possible.
- Write modular, reusable code so other PlayPath projects can borrow systems.
PlayPath is the open-source game development platform by SJA Pathway that hosts NEXUS and other community games. It's designed for developers, artists, and enthusiasts to collaborate on creative games — powered by Unity, C#, and free cloud tools. Anyone can contribute, learn, and build playable games for free.
Each project lives under projects/<project-name> within the same Unity repository.
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Have an idea for a new project? Open an issue with the proposal label.