Last man standing! Defend the city!

Enemy troops invaded the city. Grab your gun and defend the city. Look out for air supplies; loot will help you to achieve your goal.
Exciting mechanics;
-Simple on hand joystick control
-Different weapon choices
-Special bullets to enhance session experience
-Variant maps
-Special gacha system to upgrade your character
-Hero types to unlock
-Positive and negative door system to boost your damage