Here is the full list of all 23 Walhall achievements.
It gets spiky
Like a blue hedgehog!
As if it wasn't hard enough
Deceiving death itself
Gotta shoot fast
One after the other!
Babies make you tougher
You're gonna love 'em
Copying enemy movements
A new challenger appears!
Helps hitting your target
Button 2 is more useful now
He lost his drill for...
You're feeling tough
At last you can watch it
Speed up!
Your actions are under control
Take me seriously!
I'm gonna catch you!
He also wants to hit
REAL blue hedgehog!
Thank you for playing!
You're the real champion!