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