Here is the full list of all 61 Chrono Crystal achievements.
Cost 500 coins.
Cost 5000 coins.
Cost 20000 coins.
Cost 50000 coins.
Cost 100000 coins.
First time to defeat the enemy.
Defeat 500 enemies.
Defeat 5000 enemies.
Defeat 10000 enemies.
Defeat 50000 enemies.
Defeat 100000 enemies.
Rescue 1 villager.
Rescue 25 villagers.
Rescue 100 villagers.
Rescue 500 villagers.
Rescue 1000 villagers.
No Villager Deaths in a level.
Complete a level with HP over 60%.
Complete a level with HP over 90%.
Complete a Level with Untouched Crystal.
Unlock the Twilight Forest.
Unlock the Gold Minefield.
Unlock the Frozen Tundra.
Unlock the Fiery Volcano.
Defeat the Pirate King.
Defeat the Spotted Dragon.
Defeat the Elf Queen.
Defeat the Inflamation Dragon.
Defeat the Genie.
Defeat the Giant Guardian.
Defeat the Frost Dragon.
First time to repel the Demon King.
Defeat the final phase of the Demon King.
Win the first stage with 3 stars.
First time to complete a level in hard mode.
First time to complete a level in hell mode.
Complete all main levels.
Pass all main levels in easy mode with 3 stars.
Complete all main levels in hard mode.
Pass all main levels in hard mode with 3 stars.
Complete all main levels in hell mode.
Pass all main levels in hell mode with 3 stars.
Find the Wolf King and have him kill 10 enemies.
Find all the hidden Rock Crabs.
Release all Icerock Crab.
Build 50 towers.
Build 100 towers.
Build 500 towers.
Build 1000 towers.
Use the hero's active skill 10 times.
Use the hero's active skill 50 times.
Use the hero's active skill 100 times.
Draw 50 cards.
Draw 100 cards.
Draw 500 cards.
Draw 1000 cards.
Unlock all heroes.
Upgrade 1 hero to 5 stars.
Unlock all towers.
Upgrade 1 tower to 5 stars.