Here is the full list of all 25 Danmaku Unlimited 2 achievements.
Beat stage 4 in Classic Mode.
Collect one billion points.
Beat stage 5 in Classic Mode.
Beat stage 2 in Burst Mode.
Beat stage 3 in Burst Mode.
Beat stage 4 in Burst Mode.
Beat stage 5 in Burst Mode.
Reach the rank of Squadron Captain.
Reach the rank of Colonel.
Collect one trillion points.
Reach the rank of Master Sergeant.
Beat stage 2 in Classic Mode.
Beat stage 1 in Classic Mode.
Reach of rank of Sergeant.
Beat stage 1 in Burst Mode.
Beat stage 3 in Classic Mode.
Complete the game in Classic Mode.
Complete the game in Burst Mode.
Reach the rank of Flight Lieutenant.
Reach the rank of Wing Commander.
Reach the rank of Major.
Reach the rank of Ace.
Beat the game with no weapon upgrades.
Collect 100 million points.
Defeat the True Boss.