Koi Drift: Zen Koi Puzzle

Still water. One koi. Read the way it means to swim, then let the river have it. Koi Drift is a quiet logic puzzle painted in watercolour on washi paper. Each koi swims only the way it faces. Tap one whose way is clear and it glides out of the pond, leaving rings on the water; tap one that is blocked and it bumps softly and swims back. There is no penalty for a wave, only a pond to read again. Release every koi in the right order and the last ones rush out in a shimmering chain. The river runs through 400 ponds in eight seasons, each pond checked solvable by a solver. Spring brings stones that narrow the way, summer lotus gates that open and close with every koi, the rainy season frogs on lily pads, autumn leaf eddies that turn a koi's path. In winter frozen koi thaw, plum time brings turtles that turn instead of bumping, the spring flood brings reed currents, and moonlight gathers…