the game loop consists of gather resources build a wall gather more resources as enemies destroy wall repair/ rebuild bed build offensive weapon and recruit minions to aid/ maintain your defense as enemies become stronger. waves of enemies attack with more powerful attackers until the Big Boss shows up and attempts to destroy all walls and defensed built.
Core Loop:
Build barriers to keep the bad guys out.
Race to repair and reenforce the barriers till they are maxed and have the ability to attack the Badguys.
Get defeated and spend resources to upgrade your work force.
Restart and build better walls to keep more enemies at bay till you can attack and defeat more enemies to get superior resources for better upgrades.
Continue this pattern until all waves are defeated and you can defeat the Big Boss Guy.
Subloop:
collect resources to build barriers to defeat bad guys to collect resources to build better barriers (repeated gameplay loops