Here is the full list of all 50 Kill The Bad Guy achievements.
Finish Level T666
Kill the Bad Guy 250 times
Cut off 15 heads
Kill 10 Bodyguards
Cut off 5 heads
Kill 5 Bodyguards
Make the Bad Guy watch 50 movies
Associate 1000 items
Make the Bad Guy run 5000 meters
Spend 35 hours playing the game
Spill 500 liters of blood
Cut off 50 legs
Dismember the Bad Guy 50 times
Kill a Bodyguard
Finish Level DNKTBG
Kill 5 cops
Kill 25 innocent bystanders
Make the Bad Guy read 50 magazines
Make a pedestrian stop in front of a porn item 25 times
Cut off 10 legs
Kill 10 innocent bystanders
Associate 100 items
Get 60 teeth
Kill one cop
Kill one innocent bystander
Get 60 passports
Spill 100 liters of blood
Put a dog on a catapult
Finish Level Zombies!
Kill the Bad Guy 35 times as he's escaping
Kill the Bad Guy 50 times
Kill the Bad Guy 25 times on the same level
Fail 50 times
Fling the Bad Guy 1000 meters away
Share one image on Facebook
Spend 2 hours playing the game
Make the Bad Guy run away 25 times
Broadcast a game on Twitch TV
Kill the Bad Guy 25 times
Kill the Bad Guy 5 times as he's escaping
Keep hold of the ball for 5 seconds
Fail 10 times
Make the Bad Guy run away 10 times
Make the Bad Guy run away for the first time
Kill the Bad Guy over several days
Kill the Bad Guy 5 times on the same level
Kill the Bad Guy in one day
Commit your first assassination
Start the game
Get 396 stars