Heli Attack 3/Zone 1-3

This time there are even more drones, but again the strategy is the same. Hyper jump near the drones and hit them with grenades to get more machine gun ammo.
 * Enemies: 12x Drones
 * Weapon unlocked upon completion: DoubleShotgun

Secret weapon: Sparkplug
Don't forget to acquire the free weapon: Sparkplug. Walk to the right side of the first bridge until you are touching the rocky ground. Press Space (Modify) and S (Crouch) to fall through the bridge and onto a little ledge. Shoot five times to the right and crawl through the path you opened up to get the Sparkplug.