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