Here is the full list of all 22 FROGUE achievements.
Complete Biome 2
Freeze 10 or more bullets at the same time
Complete Biome 1
Defeat 100 Enemies
Kill 3 Enemies with 1 Slash
This will happen a lot
Reveal 100% of the Map
Kill 2 Enemies with 1 Slash
Complete Biome 3
Complete the game
Got 2 Swords
Got 3 Swords
Got 2 Chronospheres
Got 3 Chronospheres
Freeze 5 or more enemies at the same time.
Defeat 200 Enemies
Parry a Bullet
Solve a Puzzle Room
Solve a Combat Room
Defeat 25 Guardians
Defeat 50 Guardians
Use the Power of Evil