The person who will pick up loot for you and will stay in your base should not come to your base unless you have upgraded your base. I cannot seem to get the person to come back to my base so that I can upgrade it.
build a massive amount of long range tanks. Then mass produce the cheapest tank and bam you can beat every level. Make sure to have the sniper tanks hold their position though.
 "Idle Raiders"){kind=icon}
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