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