Here is the full list of all 30 Save the Ninja Clan achievements.
Level 25, ride a cloud.
Find and complete the secret ending.
Complete all the levels.
Play Pong in the game.
Level 29, play as a scroll.
Kill yourself with your own weapon.
Beat the second boss.
Level 19, crash the game.
Complete 10 secrets.
Fall for it on level two.
Attempt a level 25 times.
Die 100 times.
Attempt a level 10 times.
Beat 10 levels without dying.
Explode 50 times
Die 50 times.
Kill 50 enemies.
Beat 5 levels without dying.
Beat a level with an A+ time.
Beat the first level
Unlock something.
Collect 15 Collectables.
Beat half the levels.
Kill 25 enemies.
Level 11, go to "prison".
Beat the first boss.
Level 9, see a smiley face.
Beat level 4 with controls reversed.
Complete one secret.
Beat the third boss.