Use the Tower Overcharge Special Weapon (Advisor Zacara).
Win a mission with at least 1,000 resources remaining.
Finish all the missions in Chapter 1 in Story Mode.
Kill 1000 aliens.
Enable a Tower Augmentation item on any tower.
Use the Orbital Laser Special Weapon (General Cai).
Kill 100 aliens.
Earn a Gold Medal.
Recover a loose core.
Kill an alien carrying a power core.
Build 20 towers of any type in one mission.
Use the Reload Checkpoint option.
Save a core that is less than 10 seconds away from the map's exit point.
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.
Win any mission without selling any towers.
Earn a Bronze (or better) medal in a Single Player Mission.
Upgrade a level 1 tower to a level 2 tower.
Build at least 1 of each tower type in any single mission.
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.
Build 100 Concussion towers.
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).
Build 100 Temporal towers.
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.
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.
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.
