You'll have fun/existential horror with the esolangs wiki then, which describes thousands of languages (almost all unimplemented) in this vein: https://esolangs.org/wiki/Main_Page

For languages like Rivulet, see the non-textual category https://esolangs.org/wiki/Category:Non-textual or the two-dimensional category https://esolangs.org/wiki/Category:Two-dimensional_languages