https://www.ursinaengine.org/
A fully featured 2d and 3d game engine with a straight-forward API, making it
easy to develop games and applications. Includes features such
as reloading of 3d models, textures, shaders and code, all while in-game.
Modern UI library written from scratch, procedural models, animation and tweening,
lots of shaders for effects such as triplanar mapping, texture blending,
stencil projection, matcap, lighting and more.
Has more than 400 downloads a day according to PyPi Stats.