Ferris Wheel Fill

Ferris Wheel Fill opens at dusk at a travelling funfair: a big Ferris wheel lit with chasing bulbs, coloured gondolas swinging round, and visitors waiting in roped queues at its foot. Families, friends and couples each wear their group's colour and carry a balloon to match. The wheel brings one gondola down to the boarding platform at a time. Tap a queue and its front group walks up the steps and takes their seats when the gondola is their colour and has room for all of them; when every seat is filled, the bell rings and the wheel turns to the next one.

Groups that cannot ride yet wait on a small bench beside the queues, and the bench is the whole puzzle: it has three seats (four in the last rides), and a full bench with nobody who fits is the only way to get stuck. Undo takes back one turn at a time, restart sets the ride up again, and a hint shows the next move of a perfect run at the cost of the third star. Sixty rides in five sections bring more colours, bigger groups, gondolas of two to six seats, a VIP party that must ride first and side lines that join a queue once the groups ahead of them have moved on. Each ride has a par in turns: match it without a hint for three stars, and the stars fill the prize shelf with plush toys.

Every ride is built backwards from a full wheel and checked by a solver, so each one can be finished and its par is the true fewest turns. The daily ride, the same board for everyone on the day, is a quick brain teaser for a coffee break, and there is no clock anywhere, so it is a relaxing puzzle to take at your own pace. Each rider seated is worth five tickets and finishing at or under par scores a bonus, so every ride keeps a best score. Your stars, best turns and prizes are saved in your browser.