When comparing Moai SDK vs Gosu, the Slant community recommends Moai SDK for most people. In the question“What are the best 2D game engines?” Moai SDK is ranked 20th while Gosu is ranked 42nd. The most important reason people chose Moai SDK is:
Because it uses Lua + C++.
Ranked in these QuestionsQuestion Ranking
Because it uses Lua + C++.
Pro Gives you total control
You can use your own custom shaders and extend the language with C++. MOAI doesn't give you everything, instead it gives you the tools you need to develop any game you want.
Pro Full source code is available
So it is extendable with C++
Pro Easy-to-use particle engine
Uses a limited subset of Lua
Pro Uses Lua, with LuaJIT where possible
Pro Is used by many pro developers
Moai SDK is used by popular developers including Double Fine for their mobile game, Middle Manager of Justice, and for their Kickstarter hit, Broken Age(formerly, Double Fine Adventure.) It was also used to create the popular mobile game Bubble Ball 2.
This proves that this engine can be used to make fully-featured and fun games.
Pro API interfaces
Has options for development like Hanappe and Rapanui, providing a different way to interact with the engine.
Pro Helpful community
The Moai SDK Forum is active and users will go to great extents to answer queries, post code snippets, beta test, and even purchase and give feedback on each others' games.
Pro Helpful and detailed documentation
Although the Moai SDK is very advanced and uses complicated features, the documentation wiki thoroughly and clearly explains how to use these features, such as the Moai Cloud(a service that provides web services for your game), and multiple ways to build from source.
Gosu is not a game development framework, only a media library that happens to be suited to game development. (Kind of like SDL in the C world.) That means the interface is relatively small.
Pro Mature API, actively maintained and developed
Gosu has been under development since 2001. It is mature and has several toolkits built on top of it to provide additional functionality.
Pro Cross-platform, even mobile, using Ruby
Con Not for beginning developers
The Moai SDK has very advanced features which allow it to create powerful games. A drawback from this is that it is not very suitable for beginners.
Con Not necessarily tested or stable
Con Scarce documentation
Since it is a minimalist framework there is not that much documentation, but if you are used to reading API references and source code you are good to go!
Con Development has ceased
The last update was over a year ago. Users should not expect things to still work on future OS versions unless they're ready to fix them yourself.
Con Deploying Ruby apps is a mess
Games built with the Ruby to .exe "compiler" do nothing more than extract your source code and Ruby.exe to %TEMP%, then run it. The code is not really compiled at all. The process for wrapping games as Mac apps is a bit nicer, but you'll need a paid Apple Developer subscription to code sign the app, or users will see a warning/error when running your game.
The only way to really compile Ruby is to use RubyMotion, which does not work on Windows and requires a paid subscription on top of the Apple Developer one.
(This Con is not specific to Gosu. Deploying Ruby code has never been fun.)