Here is the full list of all 14 GetsuFumaDen achievements.
Defeat your first enemy
Obtain a third demon mask charm
Improve your sword to the highest quality
Obtain one demon mask charm
Obtain a second demon mask charm
Obtain a 1UP item
Obtain a hadouken
Obtain a second hadouken
Obtain a third hadouken
Have the god of fortune run out of money
Collect 9,999 money
Collect all defensive items
Collect all offensive items
Raise your sword power level up to 32