Will o' the Wisp is Spider at a scale you can hold in your head. Seven columns of three cards, one deck, and the family's whole idea intact: build the columns downward, and when a full king-to-ace run of a single suit comes together it is lifted off the board. Four collected suits wins. Twenty-one cards on the table against Spider's fifty-four makes it a far quicker game — and, because there is so little room to park a mixed stack, a surprisingly sharp one.
Every convenient move builds a stack you cannot lift. Dropping a heart eight on a spade nine is legal and often useful, and it also means those two can never travel together. On a seven-column board you run out of places to unpick that very fast, so ask before each drop whether you will be able to undo it by playing.
Empty a column, and think hard before filling it. A space is the only place a long mixed stack can be dismantled — and it is also the thing that stops you dealing. The stock will not deal while a column stands empty, so an empty column is a resource with a price attached.
Chase the face-down cards early. Only fourteen are hidden, two per column, and every one you turn is a card the rest of the game can use. Early on, a reveal is almost always worth more than a tidy build.
Count the rows, not the cards. Thirty-one cards is four full rows and a short one. Knowing how many deals you have left tells you whether to spend a column now or hold it.
The Spider family is defined by a rule no other family has: you never place a card on a foundation. A run assembled in the tableau — king down to ace, all one suit — is lifted off the board whole, and collecting them all is the win. Around that sits the tension the family is really about: you may DROP a card on any suit, but you may only LIFT a run of one suit, so every convenient move builds a mixed stack you will later have to take apart. Its members differ mostly in scale: Will o' the Wisp is the family in miniature — one deck, seven short columns, and a stock of only four rows. Mrs Mop goes the other way entirely: two decks, thirteen columns, everything face up and no stock at all. Spider itself sits between them.
Will o' the Wisp runs in your browser — free, no download, no sign-up. Install it as an app on your phone or computer and it works offline. You get unlimited undo, a hint button that names a legal move, statistics that track your wins and times, and seeded deals: every game has a seed you can replay, so a board you enjoyed (or lost) can be played again exactly.