Achievement description - Kill everyone in a mission

Achievement worth - 20G

To do this, you will of course need a weapon of some sort, thus you can first get this on the second mission; "The Massacre". Loot the shotgun near where you spawn and use the Right stick to aim and RT to shoot the shotgun at the guards as you see them. You'll need to loot the coins in the level as well, as 10 coins will give you 1 ammo once you use up the three shells that come with the shotgun. Note that guards are able to revive each other if one living guard can make it to the corpse of a dead guard, so make sure you're standing between the corpses and the other guards as you clear out the train station.