Here is the full list of all 24 The Light Brigade achievements.
Hold onto 1,000 coins at once during a run.
Finish your first run, start to finish.
Land 250 headshots. (accumulated)
Reload 100 times. (accumulated)
Try to fire your weapon without first reloading it.
Defeat the second boss.
Defeat the Father.
Land 250 gunshots. (accumulated)
Travel 1,000 meters. (accumulated)
Use an enemy's dropped weapon to kill another enemy.
After death, find your ghost and pray to it.
Kill an enemy bomber using a grenade.
Pray to the Mother.
Die and be revived for the first time.
Defeat the first boss.
Rescue an ally Light Brigade soldier out on a run.
Have a hypnotized enemy kill another enemy.
Never miss a shot during a fully completed run.
Every single shot during a fully completed run is a headshot.
Use the wishing well.
Kill an enemy sniper from far away.
Kill an enemy priest using magic.
Spend 1,000 gold at a store.
Cock an ally Light Brigade soldier's rifle.