Mech Defender is assigned to defend an entrance to the control room from zombies. wave after wave of these nasty creatures are attacking the doors. The undead come in various shapes and sizes and your Mech and additional towers should prevent these advances. Strategical placement of weaponized towers is of utmost importance. Additionally you can move your Mech freely across the room and do some extra damage to the invaders. If you want to upgrade your Mech Unit you must earn Upgrade Points and then exchange them for better weapons and upgrades for your Mech Defender. You do that in Hangar, and in armory you unlock new types of towers which will help you cope with stronger and bigger waves of Zombies. You can also get some new skills once you collect enough skill points to exchange them for. The Last Stand Mode is very interesting because there you can see just what are you made from. If you are skilled enough to defend the robot core from the even bigger and stronger Zombies.