| Alien Tears |
Earn a gold medal on all missions in the Story mode. |
| Annihilator |
Kill 10,000 aliens. |
| Arsenal |
Build 20 towers in one mission. |
| Base Defender |
Complete the Story mode. |
| Boot Camp |
Finish the first 3 missions. |
| Burn Baby Burn |
Build 5 Inferno towers. |
| Close Call |
Save a core less than 10 seconds away from the map exit. |
| Confident |
Use speed up controls for a total of 30 seconds in any one mission. |
| Death From Above |
Fire the orbital laser. |
| Diversity |
Build all tower types in one mission. |
| Eradicator |
Kill 100 aliens. |
| Exterminator |
Destroy 1000 aliens. |
| Field Promotion |
Earn at least one silver medal. |
| Filthy Rich |
Win with 10,000 resources remaining. |
| Firebug |
Beat an advanced mission with only Inferno towers. |
| First Blood |
Kill 1 alien. |
| Flawless Victory |
Earn at least one gold medal. |
| Full Defense |
Build 50 towers in one mission. |
| Full House |
Build all upgrades of all tower types in one mission. |
| Full Potential |
Beat an advanced mission with only level 3 towers and no selling. |
| Great Ball of Fire |
Build 5 Meteor towers. |
| Gun Crazy |
Beat an advanced mission with only Gun towers. |
| Happy Returns |
Recover a loose core. |
| Head Trauma |
Build 5 Concussion towers. |
| Hey! That's mine! |
Kill an alien carrying a power core. |
| High Voltage |
Build 5 Tesla towers. |
| I Spy |
Activate reconnaissance system. |
| Indecisive |
Sell 10 towers in a single mission. |
| Kaboom! |
Build 5 Cannon towers. |
| Leadhead |
Build 5 Gun towers. |
| Liquidator |
Sell 5 towers. |
| Master Strategist |
Earn a gold medal on all Challenge modes. |
| Minimalist |
Beat an advanced mission with only level 1 towers. |
| Nail Biter |
Win mission with the last core less than 10 seconds away from the map exit. |
| No Sale |
No towers sold in a single mission. |
| Not So Fast |
Build 5 Temporal towers. |
| Overseer |
Build 5 Command towers. |
| Penny Pincher |
Win with 5,000 resources remaining. |
| Pew Pew |
Build 5 Laser towers. |
| Planet Defender |
Earn a silver medal on all missions in the Story mode. |
| Power Builder |
Build 6 towers within 10 seconds. |
| Pyrrhic Victory |
Shoot down flying alien carrying a core. |
| Relay Race |
Witness 1 core handed off 10 times within 20 seconds. |
| Retry |
Reload an earlier save checkpoint. |
| Salvage Rights |
Destroy at least one boss alien. |
| Sharpshooter |
Shoot down a flying alien. |
| Shell-shocked |
Beat an advanced mission with only Cannon towers. |
| Siege Breaker |
Survive 100 waves on the Grinder challenge mode. |
| Surplus |
Win with 1,000 resources remaining. |
| The Long Road |
Alien time until exit exceeds 5 minutes. |
| The Not-So-Friendly Skies |
Build 5 Missile towers. |
| Tower Expert |
Build every tower and upgrade. |
| Untouchable |
Beat an advanced mission with zero cores captured. |
| Well Invested |
Gain 10000 resources from interest in a single mission. |
| What IS that? |
Inspect 10 aliens. |
| Xenocide |
Kill 50,000 aliens. |
| Yellow Beats Green |
Upgrade a tower. |