Every crossword here carries three clues for the same answer — easy, medium and hard — and you can switch between them mid-solve without losing what you have already filled in. It is about as close as a puzzle gets to adjusting itself to whoever picked it up.
General Knowledge is the main run and the one that keeps growing, pitched at the breadth you would expect from a Saturday newspaper. The other three are seasonal single grids: Christmas, Halloween and Thanksgiving, where the answers are exactly what the time of year suggests.
All of them solve in the browser with a timer and a small budget of help tokens, and all of them print as a clean grid with the clue list beside it and the completed answers on a separate sheet.