Here is the full list of all 16 Amaranthine achievements.
Destroy the overwatcher
Destroy the bomb
Complete level without taking any damage
Destroy 1000 enemies
Destroy 12 cargo ships in a single run
Destroy the battlecruiser
Destroy 250 enemies
Destroy 5000 enemies
Sell 100 weapons
Complete subwarp level
Complete game on normal
Find legendary weapon
Kill 10 enemies in 1 secon
Ram 50 enemies
Complete game on legend mode
Reach 20 level on legend mode