Tap to swing your axe. Whatever you chop falls into the fire, and the fire grows. That is the whole goal: make the flame bigger. Burning things earns CO2, and CO2 buys three upgrades: - Attack: a sharper axe, so things break in fewer taps - Heat: a hotter fire, so you earn faster - Target: something bigger to burn - twig, log, house, town, moon, planet, star Keep buying, and your campfire grows into something that can swallow a galaxy.