Here is the full list of all 30 10 Second Ninja achievements.
Try firing your shurikens in a boss fight.
Restart over 500 times.
Wander around a level for its duration without murdering anything.
Toggle off the leaderboards OUT OF SHAME
Finish every world.
Finish the fifth world
Drop a falling block on an enemy's head
Finish the fourth world
Finish the third world
Press restart before the timer has even begun
Make an icicle fall on an enemy's head
Finish the second world
Finish the first world with a 3 star rating
Die over 50 times
Go into the light.
Finish the first world
Shots... Shots Shots Shots Shots - die on spikes five times in a row
Skip a cutscene.
Kill two enemies with one shuriken
Spend 5 seconds or more without touching the ground
Finish a level with 0.03 or less from your next star rating (or 3 star the entire game)
Complete the tutorial.
Get your first star rating.
Fiddle around with the settings.
Finish every world with 3 stars.
Finish the second world with a 3 star rating
Finish the third world with a 3 star rating
Finish the fourth world with a 3 star rating
Finish the fifth world with a 3 star rating
Finish Hard Mode and bleed the game dry for content