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