Here is the full list of all 24 Danmaku Unlimited 3 achievements.
Defeated the True Last Boss in Graze Mode.
Graze 100,000 bullets
Graze 10000 bullets in one chain
Scored 1 Billion points.
Max out the bomb counter.
Cleared all stages in Graze Mode.
Completed Stage 5 in Graze Mode.
Completed Stage 4 in Graze Mode.
Completed Stage 3 in Graze Mode.
Completed Stage 2 in Graze Mode.
Completed Stage 1 in Graze Mode.
Completed the tutorial for Graze Mode.
Defeated the True Last Boss in Spirit Mode.
Graze 3000 bullets in one chain
Scored 100 Million points.
Flawlessly beat a boss.
Cleared all stages in Spirit Mode.
Completed Stage 5 in Spirit Mode.
Completed Stage 4 in Spirit Mode.
Completed Stage 3 in Spirit Mode.
Completed Stage 2 in Spirit Mode.
Graze 1000 bullets in one chain
Completed Stage 1 in Spirit Mode.
Completed the tutorial for Spirit Mode.