Here is the full list of all 67 Crystal Maidens achievements.
Lose 500 battles
Upgrade 30 legendary items to the level 5
Upgrade a building up to level 10
Find 10 legendary items in the Campaign Mode
Upgrade 10 legendary items to the level 5"
Upgrade 1 legendary item to the level 5
Upgrade 30 epic items to the level 5
Find 5 legendary items in the Campaign Mode
Play 500 battles with Marksman class
Upgrade 10 epic items to the level 5
Upgrade 1 epic item to the level 5
Upgrade 30 rare items to the level 5
Upgrade a skill to the level 20
Play 15 days in a row
Play 500 battles with Engineer class
Play 100 battles with Marksman class
Lose 100 battles
Earn 1 million coins in Campaign Mode
Romance 15 maidens to level 3
Play 50 battles with Marksman class
Play 500 battles with Support class
Play 500 battles with Mage class
Play 100 battles with Warrior class
Upgrade 10 rare items to the level 5
Get a hero up to level 60
Play 7 days in a row
Find a legendary item in the Campaign Mode
Upgrade 30 common items to the level 5
Earn 180 stars in Campaign 1
Lose 50 battles
Earn 250.000 coins in Campaign Mode
Romance 5 maidens to level 3
Upgrade 10 common items to the level 5
Play 100 battles with Engineer class
Upgrade a building up to level 5
Kill 1000 enemies in battle
Complete level 60 of Campaign Mode
Play 50 battles with Engineer class
Win 50 battles with all 3 stars
Play 100 battles with Support class
Upgrade 1 rare item to the level 5
Play 100 battles with Mage class
Upgrade 1 common item to the level 5
Get a hero up to level 30
Earn 120 stars in Campaign 1
Play 50 battles with Support class
Kill 250 enemies in battle
Play 50 battles with Mage class
Win 20 battles with all 3 stars
Own 10 maidens
Own 15 maidens
Play 50 battles with Warrior class
Upgrade a skill to the level 5
Complete level 30 of Campaign Mode
Romance 2 maidens to level 3
Earn 60 stars in Campaign 1
Kill 100 enemies in battle
Get a hero up to level 10
Complete 50 quests
Complete 200 quests
Complete 10 quests
Win 5 battles with all 3 stars
Earn 5000 coins in Campaign Mode
Upgrade a building up to level 2
Own 5 maidens
Complete level 1 of Campaign Mode