It's really very straightforward, Mojo jojo.
Anyone can play.
KM links refers to the link words in the Telegraph Saturday General Knowledge Crossword. 4 of the solutions link with 4 solutions in Monday's Telegraph Herculis Crossword. The KM links game is a competition to guess what the Monday words will be. seekeerz posts the words fromthe Saturday crossowrd early on Saturday morning, then folk guess what they will be linked to. seekeerz keeps score and the winner is announced every month.
MM links is a separate game where one of the players writes a little story, then posts 4 words. the game is to come up with linking words, just like the KM links, probably looking for clues in the story. The answers come out on Sunday night, crofter keeps score and the winning person for this month sets next month's link words.
It's just a bit of fun.