LittleJS is a fast, lightweight, and fully open source HTML5 game engine designed for simplicity and performance. Its small footprint is packed with a comprehensive feature set including 2D and 3D rendering, physics, particles, sound, and input handling. The code is very clean and well documented with many examples to get you started quickly.

A web-first game engine

Crown is a complete and cross-platform game engine designed for flexibility, performance, and fast-iterations.

Pixi’VN is a versatile and powerful visual novel/2D game engine. It is based on JavaScript/TypeScript and uses the PixiJS library for rendering.

A game engine with an emphasis on real-time cutting-edge solutions

Blazium Engine is a free, open-source fork of Godot for building cross-platform 2D and 3D games and applications, with the tools, platform integrations, and improvements you need.

ECS based game engine originally created for space station 14 but other games are supported. It is intended for multiplayer games and it is possible to sandbox the client.

Modoki is a TypeScript game engine and Unity-style visual editor for 2D, 2.5D and 3D mobile games. What makes it different is that it's built for AI agents. Through an MCP server, an agent like Claude Code can do almost everything a human can in the editor. It can read the live game world, edit scenes and prefabs, press Play, run builds, and check its own work with live data and rendered frames.

Gideros is a cross-platform development environment for creating games and interactive applications in 2D or 3D. It is easy to pick up, quick to develop and robust to deploy.

A powerful, beautiful, simple, and open web rendering engine

Butano is a modern C++ high level engine for the Game Boy Advance.

A powerful and intuitive toolkit that allows Blender, 3ds Max, or Maya artists to create immersive web-based experiences

An open source HTML5 game engine that empowers developers and designers to focus on content

RouteVN Creator is a free, open-source tool that lets anyone, writers, artists, hobbyists to create their own Visual Novels. No coding or technical background required.

s&box is a spiritual successor to Garry’s Mod, using Source 2 to create a modern, intuitive, moddable game development environment.

A visual programming language inspired by Scratch.

Usagi is a 2D game engine for making pixel art games in Lua 5.5. It features live reload, single-command cross-platform export, and a pause menu with input remapping built in.

A free and open-source 2D and 3D cross-platform game engine that can be used to create video games for PC, mobile devices and virtual reality or interactive content.

A free game engine written in TypeScript for making 2D games in HTML5 canvas, whether you're new to game development or you're an experienced game developer.

Gondwana is a cross-platform 2.5D game and rendering engine written in C#/.NET 8, built with SkiaSharp for graphics. It modernizes legacy Win32/GDI patterns into a modular, high-performance framework that runs on desktop, mobile, and web.

Recoil is a battle tested open-source RTS engine that, allied with a flexible Lua API, allows you to implement the perfect UI and mechanics for your game with the ability to support thousands of complex units simultaneously.

Cross-platform 2D and 3D game engine with modular architecture

Fast and lightweight 2D JavaScript library that allows everyone to enjoy the power of hardware acceleration without prior knowledge of WebGL

RPG Paper Maker allows you to create a 3D RPG with 2D sprites and 3D objects with a very simple interface

An engine designed for development teams (C++/C# programmers, 3D artists) working on interactive 3D apps

A refreshingly simple data-driven game engine built in Rust

Kaiju is a game development platform where all game scripting and logic is written in Go, combining the performance of a compiled language with the simplicity of modern syntax

A no-code, open-source, free, and easy 2D/3D game-making app

A game engine for high-performance cross-platform games

Free software game engine focusing on developing games faster