| Achievement | How to unlock
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| - Earn a gold medal on all missions in the Story mode.
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| - Build 20 towers in one mission.
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| - Finish the first 3 missions.
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| - Save a core less than 10 seconds away from the map exit.
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| - Use speed up controls for a total of 30 seconds in any one mission.
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| - Build all tower types in one mission.
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| - Earn at least one silver medal.
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| - Win with 10,000 resources remaining.
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| - Beat an advanced mission with only Inferno towers.
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| - Earn at least one gold medal.
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| - Build 50 towers in one mission.
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| - Build all upgrades of all tower types in one mission.
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| - Beat an advanced mission with only level 3 towers and no selling.
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| - Beat an advanced mission with only Gun towers.
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| - Build 5 Concussion towers.
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| - Kill an alien carrying a power core.
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| - Activate reconnaissance system.
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| - Sell 10 towers in a single mission.
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| - Earn a gold medal on all Challenge modes.
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| - Beat an advanced mission with only level 1 towers.
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| - Win mission with the last core less than 10 seconds away from the map exit.
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| - No towers sold in a single mission.
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| - Win with 5,000 resources remaining.
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| - Earn a silver medal on all missions in the Story mode.
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| - Build 6 towers within 10 seconds.
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| - Shoot down flying alien carrying a core.
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| - Witness 1 core handed off 10 times within 20 seconds.
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| - Reload an earlier save checkpoint.
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| - Destroy at least one boss alien.
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| - Shoot down a flying alien.
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| - Beat an advanced mission with only Cannon towers.
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| - Survive 100 waves on the Grinder challenge mode.
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| - Win with 1,000 resources remaining.
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| - Alien time until exit exceeds 5 minutes.
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- The Not-So-Friendly Skies
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| - Build every tower and upgrade.
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| - Beat an advanced mission with zero cores captured.
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| - Gain 10000 resources from interest in a single mission.
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| - Beats Green Upgrade a tower.
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