Build at least 1 of each tower type in any single mission.
Win a mission with at least 10,000 resources remaining.
Use the Tower Overcharge Special Weapon (Advisor Zacara).
Inspect 10 aliens.
Use the reload checkpoint option five times in a single mission.
Save a core that is less than 10 seconds away from the map's exit point.
Use the Resource Reinforcement Special Weapon (Professor Briel).
Build 20 towers of any type in one mission.
Win a mission with at least 5,000 resources remaining.
Kill an alien boss creature. (Juggernaut, Rumbler, Turtle, or Crasher)
Use the Orbital Laser Special Weapon (General Cai).
Use the Reload Checkpoint option.
Enable a Tower Augmentation item on any tower.
Kill 1000 aliens.
Kill an alien carrying a power core.
Recover a loose core.
Kill 1 alien.
Kill 100 aliens.
Earn a silver (or better) medal.
Upgrade a level 1 tower to a level 2 tower.
Win any mission without selling any towers.
Earn a Bronze (or better) medal in a Single Player Mission.
Win a mission with at least 1,000 resources remaining.
Earn a Gold Medal.
One challenge completed.
75% of all documents found.
Game completed.
One weapon fully modded and completely upgraded.
All optional tombs completed.
Bundle of dynamite shot out of the air.
200 enemies looted.
10 large animals killed and looted.
Purchased all skills in one category.
25 unaware enemies killed.
50 headshot kills performed in the single player campaign.
25% of all GPS caches found.
35 enemies killed with the pistol.
5000 pieces of salvage collected.
25% of all relics collected.
Forced an enemy to drop dynamite that killed two people.
50 enemies killed with the bow.
15 finishers performed.
25% of all documents found.
Deal 500 damage in a single turn
One optional tomb completed.
Kill 250 worms in Bodycount (multiple games allowed)
Purchase a Concrete Donkey from the in-game shop
Defeat The evil Lord Mesmer
Complete all Alien Invasion missions
Don’t allow the UFO to take any damage in level 6