LittleJS is 2D and 3D now

LittleJS has been expanded from a compact 2D HTML5 game engine into a unified 2D+3D engine while keeping its small, dependency-free core. It adds a full 3D renderer that shares the same canvas and object model as 2D, so meshes, terrain and voxel maps, collisions, shadow maps, colored lights, fog, reflections, particles, custom shaders and cameras work with the same physics, children and timers as 2D objects. 2D features also improved with dynamic lighting, one-way platforms, swept bullet collision, parallax layers and faster object collision. A Three.js rendering plugin is available for those who prefer it.

New developer tools include in-engine 2D and 3D level editors with undo, autosave and prefabs; a particle effects library and designer for fire, smoke, sparks and more usable in one line; and an example browser with 100+ live-editable samples. The rendering core was reworked for WebGL2 sprite batching and instanced 3D, yielding significant performance gains in head-to-head benches versus other engines. The API was kept intentionally small to enable AI-assisted development: an AI toolkit, a Claude Code plugin that scaffolds playable projects, a ChatGPT-based builder, and a LittleJS Arcade of 50+ open-source AI-built games. The update is driven by community demand and an ongoing game jam.