Flame
Flame — “A Flutter-based game engine.” An open-source 2D game engine built on Flutter (the Dart cross-platform UI toolkit), maintained by the Blue Fire team. ~10.6k GitHub stars; MIT-licensed; funded via OpenCollective, GitHub Sponsors, and Patreon. Source: the project’s GitHub repo.
What it is
Flame is framework-based rather than a standalone engine: it sits on top of Flutter and the Dart runtime, giving game developers a structured layer over Flutter’s rendering/event loop instead of shipping its own editor and runtime the way Godot, Unreal, Unity, or O3DE do. It is 2D-only — the first 2D engine in this wiki, which broadened from “general-purpose 3D” to all game engines (2D+3D) on 2026-06-07 to take it in.
Core features
- A game loop and a component / object system (the engine’s structural backbone).
- Effects, particles, collision detection.
- Gesture and input handling.
- Images, animations, sprites, and sprite sheets.
- Utility functions to speed up game development.
Ecosystem — bridge packages
Flame’s modular approach extends the core via official bridge packages that wire in popular Flutter/Dart libraries:
- Forge2D — 2D physics.
- Tiled — tilemap / level editing.
- AudioPlayers — audio.
- Bloc — state management.
This “small core + bridge packages” design is its analogue of the community-scaffolding / time-to-game layer the Godot sources stake out (templates + plugins) — here it’s library integrations rather than an asset store.
Licensing / business model
MIT (permissive, no royalties), maintained by the Blue Fire team and funded by community sponsorship — anchoring the open-source, no-royalty end of the engine spectrum alongside o3de and godot-engine, and contrasting with unreal-engine (royalty) and unity-engine (subscription).
Notes
- Cross-platform via Flutter: inherits Flutter’s reach (mobile, web, desktop), so its portability story is borrowed from the host UI framework, not built from scratch.
- Routed here after the hub initially parked it (2026-06-07) pending a scope call; the human chose to broaden the wiki rather than spin out a separate 2D-engines spoke.