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