Here is the full list of all 16 Gnomes Vs Fairies: Greckels Quest achievements.
You got the legendary Triple Jump Boots!
You got the legendary No-Slip boots!
You got the legendary Guitar!
You killed 100 monsters! Stupendous!
You have mastered the art of Cinder Magic
You have Mastered the Art of Ice Magic
You got the stylish Sunglasses!
You died ten times!
You died for the first time!
You killed 10 monsters! Wow!
You got the legendary Booster Boots!
You got the legendary Wall Jump Boots!
You have mastered the art of Lightning magic
You caught 100 pesky fairies!
You have killed 1000 monsters!
You have killed 5000 monsters!!