I learned about Cricklers from The English Blog. They’re a unique kind of word game. It’s hard to describe, so I’m just going to refer you to the English Blog post describing it.
They’re great English-language learning opportunities, though seem fairly difficult. I’d say high Intermediate or Advanced English Language Learners might enjoy them.
I’ve placed the link on my website under the Word and Video Games section.
Just checked out this site. I don’t like the link to Amazon at the end of each puzzle.