Kill 100 aliens.

Kill 1 alien.

Kill 10,000 aliens.

Kill 1000 aliens.

Kill 50,000 aliens.

Earn a silver (or better) medal.

Earn a Gold Medal.

Kill an alien boss creature. (Juggernaut, Rumbler, Turtle, or Crasher)

Sell 10 towers.

Win a mission with at least 1,000 resources remaining.

Win a mission with at least 5,000 resources remaining.

Win a mission with at least 10,000 resources remaining.

Build 20 towers of any type in one mission.

Build 50 towers of any type in one mission.

Sell 10 towers or more in a single mission.

Recover a loose core.

Kill an alien carrying a power core.

Upgrade a level 1 tower to a level 2 tower.

Use the Reload Checkpoint option.

Use the reload checkpoint option five times in a single mission.

Build 100 Gun towers.

Build 100 Inferno towers.

Build 100 Laser towers.

Build 100 Temporal towers.

Build 100 Meteor towers.

Build 100 Tesla towers.

Build 100 Cannon towers.

Build 100 Missile towers.

Build 100 Concussion towers.

Build 100 Boost towers.

Use the Orbital Laser Special Weapon (General Cai).

Use the Temporal Cannon Special Weapon (Colonel Rissler).

Use the Resource Reinforcement Special Weapon (Professor Briel).

Use the Tower Overcharge Special Weapon (Advisor Zacara).

Use the Core Teleport special weapon (Professor Taylor).

Use the Precision Targeting Special Weapon (Rear Admiral Phillips).

Build every tower and every upgrade for each tower.

Save a core that is less than 10 seconds away from the map's exit point.

Win any mission without selling any towers.

Build 1 of each tower type in any single mission.

Inspect 10 aliens.

Build and fully upgrade each tower type in one mission.

Using only Gun towers, Win any chapter 4 (or later) mission.

Using only Inferno towers, Win any chapter 4 (or later) mission.

Using only Cannon towers, Win any chapter 4 (or later) mission.

Using only level 1 towers, Win any Chapter 4 (or later) mission.

Complete the single player campaign in Story Mode.

Earn a silver medal (or better) on all missions in the Story mode.

Earn 100 Gold Medals on any missions.

Earn a gold medal on every mission in Story mode.

Win a chapter 4 (or later) mission with level 3 towers only and no selling.

Enable a Tower Augmentation item on any tower.

Enable a Tower Augmentation Item on 10 Towers.

Use the command shuttle to move 6 map sections in Mission 6.

Win a Gold medal on mission 19 without using the Command Shuttle.

Use the speed up control at 3x for a total of 60 seconds in any mission.

Earn Bronze on a Single Player mission.

Play a Competitive Multiplayer mission.

Earn a Victory in a DG Fighter Multiplayer mission.

Earn Bronze in a Co-Op Multiplayer mission.

Earn Gold in a Co-Op Multiplayer mission.

Finish all the missions in Chapter 1 in Story Mode.

Survive 100 waves on Grinder challenge mode on any mission.

Survive 100 waves on any Super Grinder challenge mode.

Beat a Chapter 4 mission or higher with zero cores captured.