Here is the full list of all 24 The Light Brigade achievements.
Kill an enemy bomber using a grenade.
Hold onto 1,000 coins at once during a run.
Try to fire your weapon without first reloading it.
Kill an enemy sniper from far away.
Kill an enemy priest using magic.
Cock an ally Light Brigade soldier's rifle.
Finish your first run, start to finish.
Land 250 gunshots. (accumulated)
Land 250 headshots. (accumulated)
Travel 1,000 meters. (accumulated)
Reload 100 times. (accumulated)
Use an enemy's dropped weapon to kill another enemy.
After death, find your ghost and pray to it.
Spend 1,000 gold at a store.
Pray to the Mother.
Die and be revived for the first time.
Defeat the first boss.
Defeat the second boss.
Defeat the Father.
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.