Esh. level up attributes first, say level 4 or so. buy a bomb early, only use it to destroy city (they are costly). Save money and get wall penetrator. Then extra click also virus spread. The first 30-40 days are the most important. If i do not have tank by day 30 i restart. my best is 154 days. This may not be the perfect way to start but it should get you started. If anyone can add anything plz do. I'll try it.
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