Here is the full list of all 39 IS Defense achievements.
Finish beach level
Finish the game
Finish Saint Tropez level
Call the air strike support 40 times
Call artillery support 50 times
Get all upgrades
Max the support skill branch
Max the rockets skill branch
Destroy 30 landing crafts
Survive 20 minutes on the beach
Call the cargo support 100 times
Destroy 1000 vehicles
Call infantry support 100 times
Call the helicopter support 30 times
Destroy 100 pontoons
Finish desert level
Max the player skill branch
Kill 10 000 terrorists
Destroy 250 Hummers
Max the machine gun branch
Destroy 500 vehicles
Destroy planes on the desert level
Finish harbor level
Deliver 100 headshots
Destroy 200 vehicles
Destroy the fishing boat on beach level
Destroy the Scooby mobile
Kill 3 000 terrorists
Survive 10 minutes on the beach
Destroy 100 suiciders before they detonate themselves
Let 100 pontoons land on the shore
KIll 30 000 terrorists
Survive 10 minutes on harbor
Survive 20 minutes on harbor
Survive 10 minutes on the desert
Survive 20 minutes on the desert
Fire 1000 rockets
Survive 10 minutes on Saint Tropez
Survive 20 minutes on Saint Tropez