When comparing Duality vs AndEngine, the Slant community recommends Duality for most people. In the question“What are the best 2D game engines?” Duality is ranked 30th while AndEngine is ranked 102nd. The most important reason people chose Duality is:
The full source code is available on GitHub, where the framework is actively developed. All of the editor, core and plugin code is written in C#.
Specs
Ranked in these QuestionsQuestion Ranking
Pros

Pro Open source
The full source code is available on GitHub, where the framework is actively developed. All of the editor, core and plugin code is written in C#.

Pro Great editor
Duality includes a powerful visual editing system that can be used for previewing, integrating, editing and testing game content.

Pro Live reload of code and assets

Pro Very extensible
Because both Core and Editor are completely plugin-based, Duality not only incorporates a clean and modular design, but is also very extensible - even if it wasn't Open Source. In fact, most of the standard editing capabilities comes in form of Editor plugins.

Pro Built-in physics and lighting

Pro Friendly to version control systems
It can be configured to serialize all data in a text-based format, which has been structurally optimized for version control systems.

Pro Used in commercial projects
It has been used in a production environment without burning the place to the ground. Supposedly artist-proof editor workflow with an API for tailoring the system to fit your team.
Pro Functionality can be extended
AndEngine has extensions that can add additional functionality to the engine.
Cons
Con Visual Studio required
To have possibility for scripting you have to download entire Visual Studio and spend 10 GB of free space
Con Requires windows for development
Con Abandoned
No work on the engine has been done since 2013.
Con Doesn't support current SDK
Only works on older SDK that isn't even supported anymore by google or Android Studio.
Con Poorly documented
Documentation is severely lacking.
