Here is the full list of all 22 BLACK BIRD achievements.
Finish Normal Mode.
Use a bomb when combo count is 30(MAX COMBO).
Get 1 million score points by using 1 bomb.
Become the final form by gathering green soul gems.
Get 10 million score points.
Witness her when staying 4 minutes in a stage.
Witness the last boss in True Mode.
Get 7.5 million score points by using 1 bomb.
Finish True Mode and watch this Bad Ending.
Get 11 million score points in True Mode and watch this Bad Ending.
Get 14 million score points in True Mode and watch this Bad Ending.
Get 17 million score points in True Mode and watch this Bad Ending.
Get 20 million score points in True Mode and watch this Bad Ending.
Break an electric bulb of Paladon with a back shot.
Find a big flying fish and destroy it.
Get 5 million score points in stage 1.
Get 23 million score points in any mode.
Break all 20 pots by 1 play in True Mode.
Harvest all 16 Asparas by 1 play in True Mode.
Destroy all 15 Bone Fish by 1 play in True Mode.
Get 25 million score points and watch the true ending.
Get 35 million score points in any mode.