Here is the full list of all 27 BUTCHER achievements.
Complete the game on "Hard" difficulty.
Complete the game in 1 hour on at least HARD difficulty.
Complete the game in 45 minutes on at least HARD difficulty.
Complete the game in 1.5 hour on at least HARD difficulty.
Find all skulls.
Complete the game on "Harder" difficulty.
Find 30 skulls.
Unlock new difficulty mode.
Find 20 skulls.
Maul 200 enemies to death with a sawspider.
Impale 25 enemies on hook by kicking them.
Impale 50 enemies on hook by kicking them.
Kill 10 enemies with a single railgun bullet.
Find 10 skulls.
Die 200 times in total.
Complete the game on "The Hardest" difficulty.
Beat The Last City.
Beat Volcano Research Station.
Beat Jungle Outpost.
Beat Old Military Base.
Kill 1000 enemies.
Upload your level pack to the Workshop.
Beat Ironworks Facility.
Repeat a single level 10 times.
Make 200 enemies die horribly by burning alive.