Complete a combat level without using any lethal attacks.
Locate and complete the secret mission at the end of the game.
Complete all the levels in the game on the highest difficulty.
Complete all levels in the game on normal difficulty or higher.
Fully upgrade all pistol settings.
Fully upgrade all rifle settings.
Complete all levels in the WW2 campaign.
Complete all levels in the WW1 campaign.
Complete all levels in the Civil War campaign.
Punch a horse in the face, killing it.
Kill at least 25 NPCs with your bare hands.
Die of suffocation underwater.
Kill yourself with an explosive device.