** Update 3/21/11
As of right now some people are saying this is glitched for them... If there is a workaround I will post it as soon as I know! **
In Anarchy mode, whenever you see an enemy that is glowing blue and has the words "Team challenge" above him, you and your team must perform the given action to that enemy in order to get the team challenge. (See full list below)
Tip - If you don't know what a particular challenge means, hit the BACK button and it will give you a short description of the challenge.
Examples:
Double Penetration - Have two or more teammates shoot an enemy at the same time to kill him.
Slam Dunk - Have one teammate use thumper and make the enemy fly into the air, and have another teammate use thumper on the airborne enemy.
Some challenges involve hitting the enemy into an environment hazard.
Example:
Make a wish - In Grand Central, have one guy either kick or leash the enemy into the air, and have another teammate kick him into the fountain in the middle of the map.
These really aren't too hard if you are playing with a halfway decent team, and the achievement will come in no time.
Here is the complete list of Team Challenges:
Double Penetration - Kill an enemy with a teammate while both firing bullets.
Bullet Kick - Have a teammate kick an enemy and another teammate shoot him while in the air.
Bullet Slide - Have a teammate slide-kick an enemy and another teammate shoot him while in the air.
Pricked - Have a teammate get an enemy into the air, and another teammate kick/leash him into a cactus.
Voodoo Doll - Have a teammate get an enemy into the air, and another teammate kick/leash him into the walls with pointy objects sticking out of them.
Shocker - Have a teammate get an enemy into the air, and another teammate kick/leash him into any electrical object.
Feeder - Have a teammate get an enemy into the air, and another teammate kick/leash him into a Venus Man-Eater
Vertigo - Have a teammate get an enemy into the air, and another teammate kick/leash him off a huge drop.
Tug-O-War - Two teammates must simultaneously leash and pull at an enemy.
Blood-Bath - In the level Turbine, have a teammate get an enemy into the air, and another teammate kick/leash him into the Juicer.
Make A Wish- In Grand Central, have a teammate get an enemy into the air, and another teammate kick/leash him into the fountain in the middle of the map.
Man Crush - In the level Junk Yard, have a teammate get an enemy into the air, and another teammate kick/leash him into the giant car crusher down on the lower level of the map.
Not In Kansas - In the level Dead Rock, have a teammate get an enemy into the air, and another teammate kick/leash him into the giant tornado in the center of the map
Blood Fountain - In the level Waterworks, have a teammate get an enemy into the air, and another teammate kick/leash him into the river.
Ground Chuck - In the level Power Plant, have a teammate get an enemy into the air, and another teammate kick/leash him into the Grinder.
Das Boot - Have two teammates simultaneously kick an enemy.
Slam Dunk - Have a teammate thump an enemy into the air, and have another teammate thump the airborne enemy.
Nom Nom Nom - In Dead Rock, have a teammate get an enemy into the air, and another teammate kick/leash him into the giant dinosaur skeleton head.
Meatspin - In Grand Central, have a teammate get an enemy into the air, and another teammate kick/leash him into the revolving doors in the corner.
Trapshooting - Have a teammate thump an enemy into the air, and another teammate shoot the airborne enemy.
Mercy - Have a teammate shoot an enemy in the balls, and another teammate kick/shoot his head off when he is kneeling down.
Trip Wire - Have a teammate shoot an enemy in the legs while the enemy is running, and another teammate kill him while he is on the ground.
** Again, if you forget these, they all can be seen in the game if you press the BACK button. **