Despite superior firepower and maneuverability, the Green squares are on the run from Blue's numerical advantage. Your job: fight a desperate rearguard action against the oncoming blue horde. Buy as much time as you can for the fleeing refugees. Godspeed.
I'd heard about love2d, but never tried it. While waiting for Unity3D to install for my main group project, I decided to give it a shot. As it turned out, I got a lot farther with the Love2d project than with Unity.