Do you need a game engine in C under the WTFPL license and similar ones, do they exist in nature?

Question

Game development

In general, an engine in C (pure) is required, possibly using others, but the main filling is in C.
Also licensed under WTFPL or similar (do whatever you want with the source)

Answer 1

https://en.wikipedia.org/wiki/List_of_game_engines
absolutely no one will let you do anything in a license for a complex product, but there are open licenses that do not oblige you to disclose the sources of derivative products, usually this is more than enough like mit / zlib, etc. .P.