You are a living bioweapon, a genetic amalgam of plant DNA sent to blanket a nation in vines. You need water to grow, and capturing the sources of water (fire hydrants) on each level lets you grow faster. You win once all water sources are controlled.

WASD or right click + drag to pan the camera

Zoom with the mouse wheel

Left click to place vines

1-4 to change the vine type

When a vine is placed on an enemy, that enemy will be constricted and damaged. Grow your body to envelope and destroy them. Vines severed from the heart will die. 

Basic vines are cheap but simple. Thorny vines are tough and deal greater damage. Eye vines allow you to see further. Toxic vines create clouds of poisonous gas.