Cowardly attack an unarmed enemy.
Blow up an enemy with a grenade.
Kill more than one enemy with the same plasma bullet.
Get abducted by an alien ship.
Equip a Machine Gun.
Equip a flamethrower.
Equip a Shotgun.
Equip a plasma weapon.
Equip a bazooka.
Equip a mini gun.
Defeat Titanium Wing.
Complete the desert stage.
Defeat Matrix Mind.
Defeat the Rustland Raiders.
Defeat the Nebula Raider.
Defeat Cosmic Lord.
Watch a farmer defeat an alien, proving that the fields are fighting back.
Kill 25 enemies.
Kill 50 enemies.
Kill 75 enemies.
Kill 100 enemies.
Kill 125 enemies.
Complete the area 41 stage.
Complete the elevator stage.
Complete the sewer stage.
Complete the road stage.
Complete the farm stage.
Complete the mothership stage.
Open a gate with a keycard.
