Cairn Stack the Ridge

Dusk on a high mountain ridge. The trail needs markers, and you are the one setting the stones — one at a time, onto a cairn that leans under every one you place. Cairn is a balance-stacking puzzle with a hook you can read in one screenshot: you don't drop to match a colour, you choose WHERE across the top to set each stone. Every stone set off to one side loads weight onto that side and the whole cairn LEANS. Lean it too far and it TOPPLES — and the course is lost. The twist that turns it from a stacking-toy into a puzzle is REACH. A stone only reaches so far past the one beneath it, so once a cairn starts to lean you cannot always simply counter it — you have to READ the lean early and set each stone to keep the moment near zero while you climb. Balance is the whole game. Reach the waypoint's marker line and you may CAP the cairn to bank it and move up the trail. But here's the…