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