Gosu vs Superpowers
When comparing Gosu vs Superpowers, the Slant community recommends Gosu for most people. In the question“What are the best 2D game engines?” Gosu is ranked 50th while Superpowers is ranked 71st. The most important reason people chose Gosu is:
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.
Ranked in these QuestionsQuestion Ranking
Pros
Pro Lightweight
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
Pro Collaborative
You can spin up a server and work with other people at the same time.
Pro Supports both 2D and 3D
This isn't a 3D with 2D on the side type of engine. The scene-editor supports both 3D and 2D views, allowing ease of use no matter what type of game your making.
Pro Plugin based
The community can develop and release their own plugins to add additional features making game development easier. All of these plugins can be easily downloaded in the app.
Pro Lots of handy built-in editors
It's got a scene-editor, cubic-model creator, text-editor, 2D image / animation importer, and a very useful tile-map editor.
Pro Easy to use programming language
Games can be published to the web with good performance, and the game-framework utilizes TypeScript to make programming games a little bit nicer.
Cons
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.)
Con Not frequently updated
Although it's got very nice features as is, and the team does respond to issues at a pretty good rate, the engine itself takes a little while to get updates. It's a 3-4 person team, and they need to work jobs on the side in order to bring in income.
Even though the updates come out a little slower than other engines, the team is still very much committed to the project and still support it well.
