Here is the full list of all 74 Kingdom Rush achievements. It takes around 20-25 hours to unlock all of the achievements on Windows.
Have at least 3 Imperial Guards survive in the Citadel.
Throw 500 or more axes.
Have a single barbarian kill 10 enemies.
Drop 1.000 or more bomblets with the cluster bomb.
Have your Paladins heal a total of 7.000 life.
Kill 10 or more sheep with your hands.
Change soldiers' rally point 200 times.
Help Fredo escape.
Find the elusive acorn.
Complete the campaign.
Earn 30 stars.
Defeat Vez'nan.
Sell 30 towers.
Kill 50 enemies by poison damage.
Hold 500 or more enemies with Wrath of the Forest.
Disintegrate 50 or more enemies.
Sell 5 towers in a single mission.
Build 4 Tesla towers in any stage.
Recruit max elves at The Silveroak Outpost.
Catch a fish.
Kill 10.000 enemies.
Have your Paladins perform 100 Holy Strikes.
Kill 300 enemies with electricity.
Build all 8 towers specializations.
Train 1.00 soldiers.
Have your soldiers regenerate a total of 50.000 life.
Defeat J.T.
Send 1.000 soldiers to their deaths.
Free the sasquatch on the Icewind Pass.
Build 150 towers.
Earn 15 stars.
Defeat The Juggernaut
Train a hero up to max level.
Upgrade all basic tower types to level3.
Kill 100 enemies with meteor showers.
Build 100 towers.
Kill 2.500 enemies
Train a hero up to level 5.
Use Rain of Fire 5 times in a single stage.
Open 5 information cards.
Build 30 towers.
Call all waves early in a single mission.
Call 10 waves early.
Kill 500 enemies.
Kill one enemy.
Call a wave within 3 seconds of the icon showing up.
Earn 45 stars.
Polymorph 50 enemies into sheep.
Summon 5 rock elementals in any one stage.
Shoot 100 missiles.
Snipe 50 enemies.
Teleport 250 or more enemies.
Complete all heroic stages.
Complete all iron stages.
Defeat Sarelgaz and its minions.
Defeat Gul'Thak and its minions.
Defeat Greenmuck and its minions.
Do not let The Kingpin escape.
Defeat 10 Troll Pathfinders while they're treading on ice.
Find the 5 legendary lost ice-shrooms.
Defeat Ulguk-Hai the Troll Warlord.
Have your soldiers survive the explosion of 300 demons.
Defeat 9 legions before they replicate.
Defeat Moloch the Demon Overlord.
Defeat Myconid, the Rotten Fungus.
Kill 25 Shrooms without them poisoning your soldiers.
Have your Elves deal 10000 points of damage.
Capture the attention of the mysterious crow.
Discover the hidden monster under water.
Defeat Lord Blackburn to avoid war between kingdoms.
Find the ninja master rat.
Kill 15 Wererats before they sicken any soldier.
Complete the campaign in Veteran mode.
Fire the Sunray 20 times.