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