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