On level 58, use the shield, lightning, and the slow time. Use lightning as much as possible while moving in a circle, use slow and then the shield while waiting for lightning to recharge. Basically, you mindless shoot and try to dodge the flying enemies.
I keep getting it on the sixth day. I don't like the fact that it is based mostly on luck the first two days, which just happen to be the most pivotal days to earning money.
First Day buy height, Second Resistance and Speed, Third Gider. After that...I have not a clue. I can reach the 6000 on day 21. The hard badge probably should be an impossible one.
I have a serious issue with challenge 4. What I mean to say is, I could deal with the random, non-intuitive movements of the AI until challenge 4. It is just plain ridiculous.
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