When comparing MonoGame vs GameGuru, the Slant community recommends MonoGame for most people. In the question“What are the best 3D game engines?” MonoGame is ranked 22nd while GameGuru is ranked 39th. 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 Designed for ease of use
Simplicity and accessibility are the core design goals of FPS Creator Reloaded.


Pro Active and helpful community
Users share ideas, help, and advice through the official forums. The community also provides a wealth of free assets, and the GameGuru Assets Store sees constant additions.

Pro Continuous development and updates
News and improvements are released on a monthly schedule. Interaction between The Game Creators and project backers is excellent.


Pro Awesome tech support

Pro Easy to use your own custom assets
Easily import your own 3D models with the built-in importer and create custom characters with the Character creator. Custom weapons are much more difficult, though.
Pro Massive community of users
The gamer creator forums have a large number of users, developing games, making models for sale and to give away for other users. They answer questions, help each other with problems in their games, and can make using this software so much more fun and easy.
Pro Royalty free
Games you publish with GameGuru can be sold without any restrictions or commissions.
Pro Easy to use editor
An easy 3D editor to create your own maps in seconds with drag-and-drop function.

Pro Friendly GUI
Awesome friendly GUI, and quite easy to use.
Pro Building editor
Currently in development but already looking very good! Easily create big and customized buildings with default building blocks and share them with others.
Also very easy to use in the designer: The buildings are treated like entities but still directly available in the 'building editor mode'.
Pro Powerful scripting language
Uses Lua.
Pro Large asset store
A store where you can buy various assets for your games like sounds, 3D models, weapons... Very good prices and a lot of assets are even free.

Pro Feature priorities are chosen by the community
The Game Creators team frequent the forums and ask the community for feeback and suggestions both there and via an open poll on the website. They have a great history of reading suggestions, viewing screenshots, and generally working with the community.
Pro Optimised engine for editor
The game engine is optimized for efficient use of memory.
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 Slow
Everything takes ages..feels like Unreal 4
Con Lack of user-interface
Although you can customize a lot, the user-interface does not show that. But plans are in place to improve this with some front facing GUI into the LUA scripts so you don't need to code as much.
