When comparing Codea vs Crafty.js, the Slant community recommends Crafty.js for most people. In the question“What are the best 2D game engines?” Crafty.js is ranked 37th while Codea is ranked 107th.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Helpful code editor
Errors show up live, as you type. Smarter autocompletion picks up your local and global variables, including nested types. Everything else is just plain smarter, from indentation to highlighting.
Pro Ships with music and sound packs
Codea ships with three great music and sound packs, composed just for Codea and free for you to use in whatever you create.
Pro You can code on an iPad and easily distribute the game
Pro Location library
Location library lets you make use of the GPS inside your iPad. Get your latitude, longitude, altitude and more with a dead-simple API designed specifically for Codea.
Pro Javascript
Pro Eventbinding
Easy to learn, based on Entities and Components, the later being class-like objects that entities inherit.
Pro Modular
Has open function binding systems, allowing easy creation of custom components.
Cons
Con No IDE
If you like having some huge GUI akin to Gamemaker, Unreal, Unity, etc, Crafty is not for you.