Here is the full list of all 30 Let's! Revolution! achievements.
Defeat the King with the Witch.
Defeat the King with the Hunter.
Defeat the King with one health remaining.
Defeat the King on NG+5.
Escape a level with 5 or more visible enemies.
Complete a run without taking any damage on Normal or harder.
Defeat the King with the Charger.
Defeat the King with the Oracle.
Hold 100 gold.
Defeat the King with the Shadow.
Max out your Health.
Hide 4 enemies with a Smokebomb.
Defeat the King with the Trooper.
Defeat the King.
Defeat the King without stepping on any enemies.
Hit 4 enemies with Roundhouse.
Reach Beebom City.
Max out your Energy.
Defeat a Heavy Guard.
Defeat three or more enemies in one turn.
Complete the tutorial.
Unlock all skills and items.
Catch the King without killing any enemies.
Hit 6 enemies with Armageddon.
Maintain your Charge for 15 turns.
Hit an enemy for 5 damage.
Perform Premonition for 0 Energy.
Perform a Slash for 0 Energy.
Finish a run on normal or harder in under 10 minutes.
Recieve a complimentary Bubbleship Ticket from Chovy.