Complete the indicated task to unlock the achievement.

Achievement	How to unlock
Fjolnir	Defeat the fourth boss.
Fox And Duck	Unknown.
Murderer	Unknown.
Murmur	Defeat the third boss.
Ninja	Get all gold medals.
Seven Bronze	Get 7 bronze medals.
Seven Gold	Get 7 gold medals.
Seven Seconds	Finish a level in 7 seconds or less.
Seven Silver	Get 7 silver medals.
Skellymoose	Defeat the first boss.
Ubbe	Defeat the second boss.