Here is the full list of all 22 Touhou Luna Nights achievements. It takes around 8-10 hours to unlock all of the achievements on Windows.
Start the game.
Defeat 100 minor enemies.
Defeat Meiling.
Defeat Marisa.
Defeat Patchouli.
Defeat Remilia.
Defeat Nitori.
Defeat Flan.
Defeat Reimu.
Beat the game.
Beat the extra stage.
Uncover 100% of the map.
Collect all of the weapons.
Destroy all of the gems in the hidden rooms.
Throw all vending machine cans in the trash.
Defeat any boss in 10 seconds (not counting when time is stopped).
Beat the game without using any continues.
Earn an S rank in Boss Rush.
Earn an A rank in Boss Rush.
Earn an B rank in Boss Rush.
Collect all of the items.
Unlock all of the achievements.