When comparing Kivy vs Ren'Py, the Slant community recommends Ren'Py for most people. In the question“What are the best 2D game engines?” Ren'Py is ranked 39th while Kivy is ranked 53rd. The most important reason people chose Ren'Py is:
Available on Windows, Linux, OSX, iOS and Android.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Kv design language
Kv design language is designed to work well with scalable graphical user interfaces (GUIs) as one of its primary focuses. It also segregates the logic from the design elements, making them easier to visually distinguish from each other.
Pro Multitouch gestures
Pro Cross-platform
Available on Windows, Linux, OSX, iOS and Android.
Pro Active and friendly community
Pro Reasonably good at creating puzzle and point-and-click games
Cons
Con Documentation & examples are terrible
Terrible documentation & not too many resources can be found.
Con Very difficult to deploy to various platforms, like Android
Con Not for every genre
While technically capable of creating 2D games in any genre, Ren'Py excels in creating visual novels and has a reasonable feature set for creating puzzle and point-and-click games. Other genres are best tackled by other engines.
Con Outdated Documentation and official built-in tutorials
Unfortunately, you will have to hunt relevant info on how Ren'py script works. The Ren'Py dev has the working tutorials on his Patreon, other than that you might as well just code in Python.