// the find
o2-engine/o2
2D Game Engine with visual WYSIWYG editor and JS scripting
o2 is a C++ 2D game engine with an embedded visual editor and JS/TS scripting, aimed at solo and small-team developers who want a Unity-style workflow without Unity. It targets desktop, mobile and web from one codebase, with the editor itself built on the engine's own UI toolkit.
CI actually proves cross-platform claims: Windows, Linux, macOS, iOS, Android and WASM each have their own build workflow, not just a README promise. There are 2470 GoogleTest cases including headless and rendered runs with an app test driver that injects input and takes screenshots - rare rigor for a project this size. Reflection and serialization are code-generated (CodeTool) and used to drive animation-by-field, automatic C++/JS binding, and editor property panels, so it's a real architectural investment rather than a thin wrapper. You can try the editor and shipped games in a browser before cloning anything.
README says 'Now work in progress' with no tags, releases, or versioning visible - there's no way to tell what's stable versus half-built. The feature list (Spine, skinned 3D meshes, Box2D and Box3D, deferred rendering, multithreaded Metal, hardware video decode, plus AI nodes for Gemini/ElevenLabs/Veo/Kling and a built-in Claude Code agent with MCP support) is implausibly broad for 293 stars and one visible core team - breadth this wide on a project this size usually means several subsystems are thin or unmaintained. Getting started requires a separate repo (o2-Template) with git submodules; the actual build instructions aren't even in this README. The AI content-pipeline features are a strange match for a 2D engine's scope and suggest effort is split away from hardening the renderer, physics and editor core.