Lone Defender

Walkthrough:
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-First upgrade accuracy
-Second upgrade velocity
-Third upgrade damage - should of been second upgrade?
-Forth upgrade - damage
-Fifth upgrade - rate of fire
-Sixth upgrade - targeting
-Seventh upgrade - explosion
-8th upgrade - rate of fire
-9th upgrade explosion
-10th upgrade - explosion
-11th upgrade - explosion
-12th upgrade - rate of fire
-13th upgrade - rate of fire
-14th upgrade - accuracy
-15th upgrade - accuracy
-16th upgrade - damage
-17th upgrade - targeting
-18th upgrade - accuracy
-19th upgrade - accuracy
-20th upgrade - Velocity
-21st upgrade - targeting
-22nd upgrade - targeting
-23rd upgrade - velocity
-24th upgrade - velocity
-Blimp: fire at the logo

Little planes - fire at the space between the shadow and the plane
Missile       - fire at the middle and hope for the best
Large plane   - fire at the second cockpit