debuff vs melonJS
melonJS has been around since 2011 and is one of the longest-running open-source HTML5 engines. It has strong Tiled support, polygon physics and a renderer that now reaches up to WebGPU. debuff is younger and smaller, and focuses on determinism, testing and coding agents. Here's how they compare as of October 2026.
Short answer
Pick melonJS if you want a mature, feature-rich engine with first-class Tiled support, physics and WebGPU. Pick debuff if you want a smaller runtime, deterministic tests and fuzzing, and an agent that can attach to your running game.
At a glance
| debuff 0.2 | melonJS 20.8.0 | |
|---|---|---|
| License | MIT | MIT (GitHub) |
| Language | TypeScript | JavaScript/TypeScript |
| Rendering | WebGL2, Canvas 2D fallback | WebGPU, then WebGL2, then Canvas 2D; shaders and post effects |
| Physics | Tile collision | Built-in polygon physics, with pluggable engines |
| Tilemaps | Tiled and LDtk | Tiled, including isometric, hexagonal and staggered maps |
| Audio | Web Audio, synth sounds | Web Audio with spatial sound |
| Full runtime, brotli | 20 kB (every debuff package) | 211 kB (bundled and minified by us); its README says about 250 KB minzipped |
| Testing | Scenarios, screenshot baselines, fuzz | Not found |
| Coding agents | MCP server for the running game, AGENTS.md, llms.txt | No llms.txt (404), no MCP server found |
| Community | Small | Established (about 6.4k GitHub stars), since 2011 |
Each library's complete prebuilt bundle (all debuff packages, melonjs, bundled and minified), compressed with brotli and measured on 17 October 2026. Tree-shaken games ship less.
Where melonJS is stronger
- Rendering. WebGPU support, shaders, post effects and even 3D/glTF scenes.
- Tiled. Deep support for many map orientations, with GPU tile rendering.
- Physics. Polygon collision and response built in.
- Maturity. Fifteen years of releases.
Where debuff is different
- Size. The whole debuff runtime is about a tenth of melonJS's bundle.
- Determinism and tests. Fixed steps and a seeded RNG make scenarios, exact replays and fuzzing work out of the box.
- An agent on the running game. debuff's MCP server lets an agent attach to your open game, read moments you flag, replay them and tune typed params you can undo. See the agent comparison.
- LDtk as well as Tiled.
Which to choose
If you need its renderer, physics or Tiled depth, melonJS is a proven engine. If you want something smaller with tests and an agent in the loop, try debuff:
npm create debuff@latest my-game