There are several alternatives to Ren'Py, but honestly, none of them are as mature as Ren'Py. I know Ren'Py has its limitations, but it is still the best option.
I have tested some other alternatives, but honestly, if you are looking for an engine to create visual novels based on your proficiency with a programming language you already know, I would still recommend learning Python and using Ren'Py.
If your concerns are different, then it is important to thoroughly study the alternatives to avoid reinventing the wheel, especially since players are very accustomed to playing with Ren'Py.
Some alternatives include:
- Godot Engine
- Unreal Engine (Visual Novel Framework)
- Cocos2d-x
- supersakura (SDL)
One important point: although Ren'Py is primarily based on Python, it allows integration with C++ code for specific tasks.