Kill 100 aliens.
Earn a Gold Medal.
Use the Reload Checkpoint option.
Upgrade a level 1 tower to a level 2 tower.
Use the speed up control at 3x for a total of 60 seconds in any mission.
Earn a silver (or better) medal.
Kill 1 alien.
Build 20 towers of any type in one mission.
Win a mission with at least 1,000 resources remaining.
Earn a Bronze (or better) medal in a Single Player Mission.
Use the Orbital Laser Special Weapon (General Cai).
Build at least 1 of each tower type in any single mission.
Kill 1000 aliens.
Win a mission with at least 10,000 resources remaining.
Using only Inferno towers, Win any Chapter 4 (or later) mission.
Earn a gold medal on every mission in Story mode.
Build 50 towers of any type in one mission.
Build and fully upgrade each tower type in one mission.
Win a chapter 4 (or later) mission with level 3 towers only and no selling.
Earn a Gold medal in a Coordinated Defense Multiplayer Mission.
Use the Core Teleport special weapon (Professor Taylor).
Build 100 Meteor towers.
Using only Gun towers, Win any chapter 4 (or later) mission.
Recover a loose core.
Build 100 Concussion towers.
Kill an alien carrying a power core.
Kill 10,000 aliens.
Build 100 Tesla towers.
Use the reload checkpoint option five times in a single mission.
Sell 10 towers or more in a single mission.
Build 100 Cannon towers.
Build 100 Gun towers.
Sell 10 towers.
Use the command shuttle to move 6 map sections in Mission 6.
Earn 100 Gold Medals on any missions.
Using only level 1 towers, Win any Chapter 4 (or later) mission.
Use the Resource Reinforcement Special Weapon (Professor Briel).
Use the Temporal Cannon Special Weapon (Colonel Rissler).
Win any mission without selling any towers.
Build 100 Temporal towers.
Enable a Tower Augmentation item on any tower.
Win a mission with at least 5,000 resources remaining.
Build 100 Laser towers.
Earn a silver medal (or better) on all missions in the Story mode.
Use the Tower Overcharge Special Weapon (Advisor Zacara).
Kill an alien boss creature. (Juggernaut, Rumbler, Turtle, or Crasher)
Complete the single player campaign in Story Mode.
Using only Cannon towers, Win any Chapter 4 (or later) mission.
Use the Precision Targeting Special Weapon (Rear Admiral Phillips).
Enable a Tower Augmentation Item on 10 Towers.
Build 100 Missile towers.
Win a Gold medal on Mission 19 without using the Command Shuttle.
Build every tower and every upgrade for each tower.
Play a DG Fighter Multiplayer mission.
Inspect 10 aliens.
Finish all the missions in Chapter 1 in Story Mode.
Earn a Victory in a DG FighterMultiplayer mission.
Build 100 Boost towers.
Kill 50,000 aliens.
Survive 100 waves on any Super Grinder challenge mode.
Survive 100 waves on Grinder challenge mode on any mission.
Beat a Chapter 4 mission or higher with zero cores captured.
Earn a Bronze (or better) medal in a Coordinated Defense Multiplayer mission.
Build 100 Inferno towers.
Save a core that is less than 10 seconds away from the map's exit point.
