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