Scurry

You have to protect the tree from lumberjacks and you can use acorn weapons for that. You buy it with acorns from the tree. Lumberjacks come from the left. Your acorns are your health, currency and ammo. You can make turrets from roots. There is a construction site from which you can buy upgrades and weapons. You get new acorns from a bird after each wave. You can give the bird acorns for more acorns in the next wave.