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