It's rather easy once you get it down. Just keep in mind that sitting back and waiting will lose you the game. Expect the map to be fluid, green and red dots will change every second. Do not fear this.
Start out by taking a few neutral small circles, then stop attacking neutral ones. Highlight all your circles, and just start spamming waves at your enemy's weakest point. This will lag your game for a bit, but every time it ended in the enemy having a handful of tiny circles with a huge amount of nanos on it, while you have almost all the circles, each with only a few nanos on them. This provides a ridiculous income, and you'd be surprised how strong a barrage of tiny attacks can be ;)
The only level too short is Easy. On Normal and Hard I found myself sitting with nothing to do, waiting for the end. One of the times on Hard, I even had time to save up enough money to replace all my economics centers with missle silos...
5/5, great game imho.
It's hard until you get the right starting strategy down, when it becomes ridiculously easy (haven't tried apocalypse yet, beat hard though).
Would love to see an improved sequel though.
Was sucking on easy for my first couple attempts, getting the hang of it... Now I'm on normal, everything fully upgraded, sitting, just waiting for the victory text... 5/5
 "The Last Stand"){kind=icon}
 "Battalion: Nemesis"){kind=icon}
 "The Last Canopy"){kind=icon}
 "Clear Vision 2"){kind=icon}
 "Protector: Reclaiming the Throne"){kind=icon}
 "Nano War"){kind=icon}
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