When comparing Gosu vs TIC-80, the Slant community recommends TIC-80 for most people. In the question“What are the best 2D game engines?” TIC-80 is ranked 49th while Gosu is ranked 50th. The most important reason people chose TIC-80 is:
The app contains tools for coding, sprite editing, map editing, sfx and music editing.
Specs
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 All tools in one place
The app contains tools for coding, sprite editing, map editing, sfx and music editing.
Pro Free
Free version already includes most features but a paid version is available.
Pro Retro-styled and restricted environment
Pixelated Software with a good retro style.
Pro Many Scripting languages' supported
Use awesome scripting languages like: Lua, Wren, Moonscript, JS, Ruby, etc.
Pro Export
Exports easily to Windows, Windows-XP, mac, Linux and HTML.
Pro Noob underdog
You can imagine this engine Shiva Lua scripting language making 2d side scrolling Megaman style games a Bandai trademark.
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.)