| 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. |
