Here is the full list of all 44 Secret Agent HD achievements.
Complete all achievements.
Finish 5 custom maps from the Workshop
Life is better in the hot tub.
Destroy 10 mecha-spiders
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Destroy crawler bot while in the air on medium or hard difficulty.
Spend at least 60 seconds under the water
Kill an enemy while wearing a jetpack
Get confused and slowed down at the same time.
Finish any level in under 60 seconds
Finish Episode 4
Complete any episode in one session without loading.
Collect all island treasure.
Collect every flag in the game
Collect 100 tombstones
L10 without killing any enemies and with a perfect health.
Kill 50 Ninja's
Finish Episode 3
Hold 6 keys in your inventory at once
Collect over $1000000 worth of bonus items
Get maximum rapid fire
Blow up enemy with a Dynamite
Catch 50 hidden coin bags
Destroy 10 tombstones
Finish Episode 2
Complete any episode without taking damage.
Complete any episode on hard mode.
Finish any episode on HARD with 35 ammo or more
Complete any level without killing any enemies
Collect 25 toothbrushes
Disable laser grid 20 timesCHIEVEMENT_DESC_23_16
Stack two barrels, one on another
Use the teleporter 50 times
Die in water
Finish Episode 1
Collect All Magnifiying Glasses in any episode
Collect all SPY letters in the right order
Finish a level with an extra key in your inventory.
Finish any level with a perfect score
Finish any level
Collect SPY letters in wrong order