Here is the full list of all 44 Age of Defense achievements.
Pass 3th mission
Pass second mission
Pass first mission
See how it begun
Wake up the old mage
Start the game
Pass 4th mission
Pass 5th mission
Pass 6th mission
Pass 7th mission
Pass 8th mission
Pass 9th mission
Meet the sky people.
Find a broken flying saucer.
Defeat Archeopteryx.
Survive the great blizzard with the help of coal.
Fight off enemies enslaved by Frostmourne.
Defeat the Giant Woolly Worm.
Witness how Zeratul saves dinosaurs from extinction by destroying a meteorite.
Find and tame Ambulocetus.
Get into the cartoon cave and watch any of them.
Kill 750 unicellular organisms.
Kill 1250 fish.
Kill 1500 dinosaurs.
Kill 2750 birds.
Kill 2250 primates.
Learn any skill.
Learn any 25 skills.
Learn all skills in any of the four skill trees.
Accumulate 99 skill points.
Learn all types of traps.
Use the magic of the sky people.
Survive on the map by fulfilling the condition on the clay tablet.
Survive on 11 maps by fulfilling the condition on the clay tablet.
Unlock the Chief mode and survive in it on the first mission.
Survive on any 9 maps in Chief mode.
Unlock Madman mode and kill the Giant Octopus in it.
Survive on all maps in all modes.
Upgrade any tower to the maximum.
Have a pet fish, a bird and a dinosaur on one map.
Learn all skills that reduce the cost of towers.
Make a voodoo mage create a meat golem.
Master the technology of stone laying.
Kill the meatball monster.