Here is the full list of all 51 Door Kickers: Action Squad achievements. It takes around 15-20 hours to unlock all of the achievements on Windows.
Kill 1000 bad guys
Get 3 stars in a mission
Successfully complete all missions in Chapter 1
Kick Open 100 Doors
Rescue 50 hostages
Get 100 kills as Assaulter
Collect your first secret item
Kill yourself with your own explosives
Kill 50 bad guys
Win one mission in Coop
Kill 3 enemies by blowing up one barrel
Successfully complete all missions in Chapter 2
Kill an enemy with an elevator
3-Star all missions in Chapter 1
3-Star all missions in Chapter 2
Rescue 50 Wounded Policemen
Disarm 30 bombs
Kick Open 1000 Doors
Blow Open 100 Doors
Stun 500 enemies
Kill 3 enemies with one breaching charge
Complete a level without taking any damage whatsoever
Use sniper support to kill 100 enemies
Set 20 enemies on fire
Unlock Chapter 2
Unlock Chapter 3
3-Star all missions in Chapter 3
Rescue 1000 hostages
Use sniper support to kill 1000 enemies
Successfully complete all missions in Chapter 3
Kill 50 Hostages
Use 5 extra lives in the same mission
Resurrect another player 5 times in the same mission
Collect all 20 secret items
Successfully complete all missions in Chapter 4
3-Star all missions in Chapter 4
Unlock Chapter 4
Make 5 VIP Arrests
Successfully complete all missions in Chapter 5
3-Star all missions in Chapter 5
Unlock Chapter 5
Get 100 kills as Breacher
Get 100 kills as Shield
Get 100 kills as Recon
Get 100 kills as Agent Fergie