It's a combination of 2D Wordle, crosswords and Sudoku. Been running for over 4 years :)
I made a simpler take on "challenging Wordle" some years ago: https://quuxplusone.github.io/wordle-clone/evirdle/ (Try "easy mode" too!)
It's a combination of 2D Wordle, crosswords and Sudoku. Been running for over 4 years :)