Here is the full list of all 48 Remaya Idle achievements.
Rebirth 50 times.
Rebirth 30 times.
Use 500 Books.
Reach Level 500
Reach Level 400
Acquire 1000 Legendary Items.
Rebirth 15 times.
Reach Knowledge Level 100.
Reach Level 300
Reach Knowledge Level 75.
Enter 100 Dungeons.
Reach Knowledge Level 50.
Reach Level 200
Rebirth 7 times.
Use 100 Books.
Reach Knowledge Level 30.
Gain 500 Equipment.
Enter 25 Dungeons.
Destroy 10000 Targets.
Enter 10 Dungeons.
Reach Knowledge Level 15.
Rebirth 3 times.
Destroy 5000 Targets.
Enter a Dungeon.
Rebirth 1 time.
Reach Knowledge Level 5.
Use 1000 Potions.
Acquire 100 Legendary Items.
Gain 100 Equipment.
Use 500 Potions.
Destroy 2000 Targets.
Use 25 Books.
Reach Level 100
Acquire 10 Legendary Items.
Reach Level 75
Gain 25 Equipment.
Acquire a Legendary Item.
Destroy 1000 Targets.
Reach Level 50
Use 100 Potions.
Use a Book.
Destroy 500 Targets.
Use 25 Potions.
Reach Level 20
Gain an Equipment.
Destroy 100 Targets.
Reach Level 5
Use a Potion.