So long as you boost regen asap and never boost max as an upgrade this game is way too easy. I didn't use anything but raiders the whole game. They are insanely powerful for their cost once they get upgraded and you can just fill the screen with them.
Way way too easy. And scoring is based on not winning fast... If you just wait around with one of the guardian orbs alive you can blast away at the generated orbs until you get bored racking up points/ether.
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