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