click tree. buy stuff to produce more trees. if you are wondering what the upgrades are, from left to right it goes: worker (to plant trees), orchard (a large plot of land to produce trees), drone (a military-grade bombing drone except it rains down seeds), and lab(produces trees out of experiments)
TREE TREE TREE TREE TREE TREE TREE TREE TREE TREE TREE TREE TREE TREE TREE TREE TREE TREE TREE TREE TREE TREE TREE TREE