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