Open Source Impact.js Alternatives

Crafty.js is a JavaScript game engine that can be used to create HTML 5-powered games. With Crafty.js, your games will be cross-browser compatible allowing any one to play your games on old and modern browsers, including Internet Explorer 9. The open source game engine allow you to build games using canvas or the native DOM, splice and dice a sprite map to easily draw game entities, and use advanced SAT collision detection that can contain more information than just true or false statements.

Three.js is a free and open-source JavaScript 3D library. The aim of the project is to create an easy to use, lightweight, 3D library with a default WebGL renderer. The library also provides Canvas 2D, SVG and CSS3D renderers in the examples.

Godot is a free and open-source 2D and 3D, cross-platform, game engine released under the MIT license. With Godot, you can develop games using Go or GDScript. Godot provides a huge set of common tools for game production, so that you can focus on making your game without reinventing the wheel. The development environment runs on multiple operating systems including Linux, macOS, and Windows and can compile games for PC, Mobile and the web browser.

Babylon.js is one of the world's leading WebGL-based graphics engines. From a new visual scene inspector, best-in-class physically-based rendering, countless performance optimizations, and much more, Babylon.js brings powerful, beautiful, simple, and open 3D to everyone on the web.

Cocos2d is an open-source software frameworks for building cross-platform games and apps.

The Unreal Engine is a game engine and suite of tools and technologies developed by Epic Games. The engine was first released in 1998 as a part of the first-person shooter game Unreal, where the game itself was built on the engine. Today the Unreal Engine has grown into an ecosystem that includes a marketplace for game assets that can help indie developer to develop games and make a living selling game assets them selves. The Unreal Engine is free to use and provides a revenue-share model for developers and has been used to tipple A studios and indie developers to create games in almost every genre, including platformers, fighting games,RPGs, MMORPGs, and many more.