Are there some game engines for pure C?

Answer 1

Sure there are. However most of them are not available for download or are too old.
The most famous game engine for pure c, that I am aware of, is Id tech 3 which was released in 1999.

Answer 2

opengl es

Answer 3

OpenGL ES is not a game engine. It is rather a subset of OpenGL which is an API for rendering graphics.

Answer 4

Here is a list of game engines showing their respective scripting and more features

https://en.m.wikipedia.org/wiki/List_of_game_engines