When comparing MonoGame vs Leadwerks, the Slant community recommends MonoGame for most people. In the question“What are the best 3D game engines?” MonoGame is ranked 22nd while Leadwerks is ranked 33rd. The most important reason people chose MonoGame is:
Support for iOS, Android, Mac OS X, Linux, Windows (both OpenGL and DirectX), Windows 8 Store, Windows Phone 8, PlayStation Mobile, PlayStation 4, Xbox One, Nintendo Switch, and the OUYA console with even more platforms on the way.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Cross-platform
Support for iOS, Android, Mac OS X, Linux, Windows (both OpenGL and DirectX), Windows 8 Store, Windows Phone 8, PlayStation Mobile, PlayStation 4, Xbox One, Nintendo Switch, and the OUYA console with even more platforms on the way.
Pro Open source
All the code is available to you ensuring you'll have the ability to make changes when you need to or even port to whole new platforms.
Pro Well-known and documented API
The framework implements the XNA 4 API, so games made in XNA can be ported to other platforms using this. This was the same API used by the Xbox Live Indie Games platform so there's lots of documentation online for it.
Pro Managed code
By leveraging C# and other .NET languages on Microsoft and Mono platforms you can write modern, fast, and reliable game code.
Pro Good community
The community MonoGame has to offer is helpful and mature.
Pro Performance on desktop
The performance on desktop platforms matches that of C++, but you still get all the pleasant features that C# has to offer.
Pro Very good entity system, did have GUI functions, easy to use terrain editor with vegetation system.
Good API tutoials, workshop elements which can be loaded from steam.

Pro Both Windows and Linux supported
Pro Built-in level editor
Has an acceptable 3D map editor that is easy to use.
Pro Versatile flow diagram script model
Leadwerks's flowgraphs resemble flowcharts where each box represents a function or value, with connections between them representing program flow. This provides a better at-a-glance indication of game logic than a simple list of events, and makes complex behaviors easier to accomplish.
Pro Community forum offers plenty of support
It makes game developing much easier if you have someone backing you up when you run into a bug or other issues, and get replies within hours .
Pro Decently sized library of tutorials for both Lua and C++

Pro Very clean and easy C++ API

Pro Lua scripting support
Pro Reasonably priced
Standard edition of Leadwerks costs 92,99€. Additionally, it often goes on sale on Steam.
Pro C++ scripting support
Pro Terrain editor
The terrain editor allows sculpting, paint, vegetation placement and importing of external maps. Especially the painting is done very well and can lead quickly to very professional looking results.
Pro Easy to use API and scripting language
Cons
Con Slow rate of updates
Versions 3.9 is overdue by a year, and version 4.0 is set to release in 2040.
Con Non-Windows tools are a bit funky
Monogame support for Xamarin Studio or Monodevelop is a bit shaky especially for library references. Only good non-Windows IDE compatible with MonoGame is Rider and that costs money & isn't open-source.
Con Little to no support
This product relies on community support, although some members are helpful and quite approachable they don't like to share their secrets with people that are new to programming.
The product is sold as a Full featured platform but it seems to more in the Alpha stage of development as a lot of the good aspects where taken out in previous versions.
Con Has a track record of broken promises
Con Forums are poorly run and censored
Con Highly misleading advertising
Con Only prefabs made with the Leadwerks IDE could be used.
The two main problems for me is that C++ is not as easy to use like LUA. The IDE should also support C++. The secons is that only prefabs can be used which are made with the IDE. So you can not easy made a game that can be modded by the user.
Con Weak out-of-the-box AI
The only AI movement function is going in a straight line.
Con Very buggy
Leadworks is a not complete, it's a work in progress. As such many parts of the engine are clunky, especially the level editor.
