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.
Send 1.000 soldiers to their deaths.
Defeat J.T.
Upgrade all basic tower types to level3.
Kill 2.500 enemies
Defeat The Juggernaut
Build 150 towers.
Build 100 towers.
Kill 100 enemies with meteor showers.
Earn 15 stars.
Train a hero up to max level.
Open 5 information cards.
Train a hero up to level 5.
Kill 500 enemies.
Use Rain of Fire 5 times in a single stage.
Build 30 towers.
Call a wave within 3 seconds of the icon showing up.
Call 10 waves early.
Call all waves early in a single mission.
Kill one enemy.
Earn 30 stars.
Build all 8 towers specializations.
Change soldiers' rally point 200 times.
Earn 45 stars.
Kill 10.000 enemies.
Have your soldiers regenerate a total of 50.000 life.
Train 1.00 soldiers.
Sell 30 towers.
Sell 5 towers in a single mission.
Recruit max elves at The Silveroak Outpost.
Have at least 3 Imperial Guards survive in the Citadel.
Free the sasquatch on the Icewind Pass.
Catch a fish.
Polymorph 50 enemies into sheep.
Have a single barbarian kill 10 enemies.
Hold 500 or more enemies with Wrath of the Forest.
Have your Paladins heal a total of 7.000 life.
Have your Paladins perform 100 Holy Strikes.
Kill 300 enemies with electricity.
Drop 1.000 or more bomblets with the cluster bomb.
Summon 5 rock elementals in any one stage.
Build 4 Tesla towers in any stage.
Kill 50 enemies by poison damage.
Shoot 100 missiles.
Snipe 50 enemies.
Throw 500 or more axes.
Kill 10 or more sheep with your hands.
Disintegrate 50 or more enemies.
Teleport 250 or more enemies.
Defeat Vez'nan.
Complete the campaign.
Complete all heroic stages.
Complete all iron stages.
Defeat Sarelgaz and its minions.
Help Fredo escape.
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 elusive acorn.
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.