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