Here is the full list of all 41 Dropship Down achievements.
Reach 100,000 score in a 4-player game.
Earn 10,000,000 score in total.
Reach 50,000 score in a 4-player game.
Reach 20,000 score in a 4-player game.
Reach 100,000 score in a 1-player game.
Kill 1,000 creeps with the Rocket Launcher.
Reach 100,000 score in a 2-player game.
Deal 10,000 friendly fire damage.
Reach 100,000 score in a 3-player game.
Take 10,000 damage from friendly fire.
Reach 50,000 score in a 1-player game.
Spend 1,000,000 credits in total.
Kill 1,000 creeps with the Flamethrower.
Kill 10 boss monsters.
Use 1,000 pickups.
Reach 20,000 score in a 1-player game.
Reach 50,000 score in a 2-player game.
Earn 1,000,000 score in total.
Reach 50,000 score in a 3-player game.
Kill a boss monster.
Overheat your weapon 500 times.
Kill 1,000 creeps with the Sniper Rifle.
Kill 1,000 creeps with the Submachine Gun.
Earn 500,000 score in total.
Take 10,000 health damage in total.
Deal 1,000 friendly fire damage.
Take 1,000 damage from friendly fire.
Spend 100,000 credits in total.
Kill 1,000 creeps with the Pump-Action Shotgun.
Reach 20,000 score in a 2-player game.
Spend 50,000 credits in total.
Earn 100,000 score in total.
Reach 20,000 score in a 3-player game.
Spend 10,000 credits in total.
Take 1,000 health damage in total.
Lose your first game.
Earn 10,000 score in total.
Kill 100 creeps.
Overheat your weapon.
Use a pickup.
Kill 1,000 creeps with the Sidearm.