When comparing Allegro vs FlatRedBall, the Slant community recommends Allegro for most people. In the question“What are the best 2D game engines?” Allegro is ranked 12th while FlatRedBall is ranked 44th. The most important reason people chose Allegro is:
The Allegro community has produced a lot of great tutorials and resources. Allegro [Wiki](https://wiki.allegro.cc/index.php?title=Main_Page), Mike Geig's Allegro [Tutorials](http://fixbyproximity.com/2d-game-development-course/), Rachel Morris' [Tutorials](https://www.youtube.com/watch?v=E4RqHtEAAds), CodingMadeEasy's [Tutorials](https://www.youtube.com/playlist?list=PL6B459AAE1642C8B4&feature=plcp).
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Supports desktop and mobile
Support for Windows, Mac OS X, Linux, iPhone, and Android
Pro Good engine architecture
Allegro is well designed, easy to use and has many useful features.
Pro Good documentation and lots of tutorials
Since it has been in development since mid-90s with hundreds of people contributing to both the engine and documentation, it has all of its bases covered when it comes to standard support.
Pro Per-platform library optimization
Allegro uses DirectX for Windows, and OpenGL for other targets.
Pro Freedom to implement your own game engine
You are not bound to the limits of existing game engines, and you can actually implement your own engine.
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 Learning curve for hobbyist developers
Hobbyist developers coding alone may experience a learning curve with Allegro of about 200 hours (if you are rusty on C++). To learn quickly, see Mike Geig's tutorials at Fix By Proximity. This learning curve may be fine if you are considering going professional, but are still unsure.
For hobbyist developers not planning on going professional, you may want to look into a complete 2D game engine, rather than a coding library. For example, there are "non-coding" engines that provide support for coded plugins or scripting. But, if you are a dedicated hobbyist planning to use Allegro as your coding library of choice, you can still develop great games as a hobbyist.
Con Isn't great for C++
If you are a fan of object oriented programming, and want to use this library, then the chances are that you are going to be creating a lot of wrappers for functions in this library.
In short, if you're a C++ person, it could be recommended to check out SFML instead.
Con The editor's UI looks dated
Although functional, doesn't look as flashy as Unity for example, which may put some people off.