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