A game like Wordle seems fall more or less halfway between a copyright and a patent. There is a lot of gray area on this one.
The name could be a trademark.
The UI treatment could potentially be trademarked.
The implementation could be copyrighted.
The game mechanics could be patented. (not 100% sure how effective this would be, especially since there might be prior art, and since as a game it may not be a useful invention)