Here is the full list of all 34 Insanity's Blade achievements.
Go through HELL with no saves!
You are an ARCADE MASTER!
Complete the Arcade adventure!
You like to live dangerously, no saves!
Play singleplayer on the day of love
Play co-op on the day of love
Upgrade Finn's axes to max level!
Play within punching distance!
Wow! 100% on all your saves!
Reach the max level!
You beat the game!
Beat the game on Casual difficulty
Get hugged by a crawler
Collect all the questy things!
Thurstan gets possessed
Beat a walking level without crouching.
Bought the 6-way magic daggers!
Get all the pointy things!
Pay your dues to the zombie priests
Get the Cock Puncher
Deliver a punishing ball kick!
Throw 'em around!
Tear 'em in two!
Use a continue on Stage 0
Revisit the How To Play video
Rip an arm off 'em!
Hey! We thought you liked it rough!
The taste of true defeat
Go corpse surfing
Die in the water
Finish Stage 0 in Hell Mode
Set a hostage free
Now you can throw daggers!
Skip the How To Play Video