Here is the full list of all 20 Tango Fiesta achievements worth 1,000 gamerscore.
Deal with a Choppa!
Kill every bad guy in a level using only one of your weapons.
Buy a gun priced over $50000.
Burn down an Objective Building.
Play through the entire game in one session with 3 friends.
Use the Matrix 80 for the first time.
Kill 120584 enemies.
Defeat Gordon Bennette using only melee attacks.
Kill Yatcha Queen solo, using only melee attacks.
Kill any boss with the last bullet in your gun.
Complete any World using only the Sawn-off and the Chainsaw.
Get the most melee kills in a multiplayer game.
Play through any World, taking damage on each level, but don't pick up any health kits.
Kill an enemy within 2 seconds of starting a level.
Defeat Old Ramishar using only melee attacks.
Achieve a bodycount of 199 in a single World.
Defeat 10 enemies in Killionaire by getting them to kill each other with their weapons.
Kill 1987 bad guys with Bionic Cop, without dying.
Get every other achievement in the game.