Balloon Invasion

Hints:
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Submitted by: David K.

Buy upgrades for your bullets and shells first, you need maximum fire power in 
later stages. 

Use air strikes sparingly to gain the maximum points for each level. 

The more points you earn the more upgrades you can buy. 

Try to keep your spending down in the early stages, where it's easier to defend 
so you can get those needed upgrades. 

You can replay levels to score better points.