Kill 500 enemies.
Complete 7 missions.
Complete 14 missions.
Complete 21 missions.
Reach a score of 500,000.
Reach a score of 750,000.
Reach a score of 1,000,000.
Get a x50 combo.
Get A rank in the game over screen.
Save 30 hostages.
Kill 1,500 enemies.
Kill 2,500 enemies.
Buy 2 hats.
Buy 4 hats.
Buy 8 hats.
Unlock 3 guns.
Unlock 6 guns.
Unlock 9 guns.
