Attack of the Red Things

An epic battle with a story line so deep that you will never understand it (don't even try), Red things from a near distant land are attacking our green thing in force. You must amass an army of Green Things to defend the other green thing. At any given time your army can consist of 30 troops. Troops can spawn once some energy is built up on the green thing. Wait longer and the troops are stronger or get impatient and send a full army of weaklings out , do what you want its your army. Melee troops are round green troops with blue pointy things that stick out, if the blue pointy thing hits a red thing it hurts them, and you (physically and emotionally). Gunners shoot their little hearts out and chase the red things until they get in range, then they plant their feet and fire away (actually its never been proven...