Here is the full list of all 20 Shank 2 achievements.
Complete Campaign Mode on Normal difficulty
Rescue 50 Civilians From The Militia
Do 10 combos of 20 hits or more
Kill 12 enemies
Defeat all the waves in any Survival Mode map
Complete Campaign Mode on Hard difficulty
Perform 100 Machete Counter Kills
Perform 60 Pistol Counter Kills
Get 30 firetrap kills in one Survival match
Reach the zombie wave in each Survival map
Kill a Survival Boss with no traps or grenades
Go 15 waves without either player dying in Survival Mode
Buy nothing for 10 straight waves of Survival
Beat a Campaign level with no ranged attacks
Find the kitchen sink and kill someone with it
Buy everything in Survival Mode
Kill 100 enemies using the shovel
Execute 150 kills with the baseball bat
Do 30 counters in one Survival match
Kill 50 enemies with the heavy object smash