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