When comparing pygame vs MonoGame, the Slant community recommends MonoGame for most people. In the question“What are the best 2D game engines?” MonoGame is ranked 9th while pygame is ranked 16th. 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 Easy Python syntax
Pygame uses Python as its scripting language. Python is widely considered one of the easiest languages to grasp even for beginners.
Pro Very easy to understand
The API is very straightforward.
Pro Good canvas system
Pygame has a drawing system that allows the user to create and draw on an unlimited number of canvases.
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.
Cons

Con Deathly slow
Con Nonexistent community
No good forums, wiki, or other ways to reach other Pygame developers.
Con Very basic
Pretty much just a wrapper for SDL.
Con Pygame is a multimedia framework, not a game engine
Physics, AI and networking are not supported.
Con Messy documentation
The docs are messy, and some basic functions are infuriating to work out. There's even some places in the documentation where it's clearly wrong about how a method is called/what the arguments really do.
Con Outdated
Pygame uses a really old version of SDL and is missing some of the features developed for SDL2.
Con Hasn't been updated in years
Hasn't been updated in years.
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.
