When comparing Crafty.js vs FlatRedBall, 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 FlatRedBall is ranked 44th.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
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.
Pro Continually improving and open source
Just check the commit frequency on github :)
https://github.com/vchelaru/FlatRedBall/commits/master
Plus Victor takes community input seriously and is known to shift around priorities based on the pressing needs of the community
Pro Very easy to use
Simplifies routine tasks such as adding entities and files to the game, or tuning parameters, via the FRB Editor called Glue
Pro Great community
Very active chat on gitter: https://gitter.im/vchelaru/FlatRedBall
Victor (the creator of the engine) is available throughout the day to answer questions and solve any problems that may arise, along with the rest of the community members who are ready to assist in any way they can.
Pro Extensive documentation
http://flatredball.com/documentation/
Very good documentation not only regarding the API details, but also lots of tutorials covering different aspects of using FRB, either on the code-side or on using any of its tools.
Cons
Con No IDE
If you like having some huge GUI akin to Gamemaker, Unreal, Unity, etc, Crafty is not for you.
Con The editor's UI looks dated
Although functional, doesn't look as flashy as Unity for example, which may put some people off.