Your position on the circle decides where you launch. Wait for the right angle, then press Space, click or tap to send your square flying. Catch another circle to ride its rim and line up the next jump. The side walls and rocky ledges bounce you onto a new route, or straight into trouble, and the ledges slope down from the wall, so where you hit them matters too. A menu click or tap only presses that button; it never launches you by accident.

The climb is generated as you go: circles and rocky ledges are laid out at random, and a ledge is only placed where it leaves you a way up. Higher up, the circles spin faster, falling rocks knock you off course, and blue circles reverse direction after every full turn. Below you, the lava never stops rising, so reading the next jump is only half the challenge. Knowing when to go is the other half.