Complete the indicated task to unlock the achievement.

Achievement	How to unlock
1,000 stars	Collect 1,000 stars.
100% Easy	Complete the game on easy difficulty or higher.
100% Hardcore	Complete the game on hardcore difficulty.
100% Normal	Complete the game on normal difficulty or higher.
15,000 stars	Collect 15,000 stars.
8,000 stars	Collect 8,000 stars.
Arcade 10	Complete 10 arcade levels.
Arcade 20	Complete all 20 arcade levels.
Arcade 5	Complete 5 arcade levels.
Arcade mastery	Complete all arcade levels with 3-star rank.
Bomber	Kill 25 enemies using bombs.
Challenge 10	Beat 10 challenge levels.
Challenge 22	Beat 22 challenge levels.
Challenge 44	Beat all 44 challenge levels.
Challenge mastery	Complete all challenges with 3-star rank.
Collector	Score total of 100,000 points in story mode.
Counterproductive	Complete an arcade level with 0-star rank.
Deadly punch	Punch 100 enemies.
Death from above	Kill 10 enemies using a falling rock.
Explorer	Find 10 secret stars.
Final boss defeated	Beat the final boss.
First boss defeated	Beat the first boss.
It wasn't in the tutorial!	Kill a hedgehog.
Living bullet	Kill 10 enemies using another enemy.
Multi kill	Kill 5 enemies by bouncing from one to another.
Obsessive Collecting Disorder	Complete a story level with perfect score.
Pacifist	Complete a story level without killing any creature.
Second boss defeated	Beat the second boss.
Speedrunner	Complete a story level in less than 5 minutes.
Stomper	Kill 100 enemies using stomp.
Super Collector	Score total of 200,000 points in story mode.
Super Explorer	Find 50 secret stars.
Third boss defeated	Beat the third boss.
Ultra Explorer	Find all 100 secret stars.
Untouchable	Complete a story level without taking any damage.