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