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