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