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