Here is the full list of all 77 Revenge of the Titans achievements.
Defeated 1 Xmas Ultrayeti
Lost 50 buildings to the enemy
Blew up 500 Titans using explosives
Lost 25 buildings to the enemy
Vanquished 1,000 Titans
New rank: lieutenant colonel
Blew up 250 Titans using explosives
New rank: major
Completed whole world at maximum difficulty
New rank: captain
Completed the Earth missions
Blew up 100 Titans using explosives
Defeated a Megatitan
Vanquished 500 Titans
Lost 10 buildings to the enemy
New rank: lieutenant
Vanquished 250 Titans
Got $5,000 in the bank
Vanquished 100 Titans
New rank: second lieutenant
New rank: warrant Officer
Destroyed a Leviathan
Destroyed a Gargantuan
Destroyed a Behemoth
Destroyed the Ultratitan!
Completed the Moon missions
Completed the Mars missions
Completed the Saturn missions
Completed the Titan missions
Completed all missions at maximum difficulty
Lost 100 buildings to the enemy
Vanquished 2,500 Titans
Vanquished 5,000 Titans
Vanquished 10,000 Titans
Crushed 25 Titans under new buildings
Squished 50 Titans under new buildings
Turned 100 3-D Titans into 2-D Titans
Fried 100 Titans with the Capacitor
Fried 250 Titans with the Capacitor
Fried 500 Titans with the Capacitor
Nuked 50 Titans from orbit
Nuked 100 Titans from orbit
Nuked 250 Titans from orbit
Researched all weapons
Researched all defenses
Researched all turret upgrades
Researched all explosive tech
Researched the droid factory
Researched all science and technology
Researched nuclear reactors
Researched the decoy tower
Researched everything
Base held together with tape and string at end of mission
Giant Titan killed within a few metres of the base
Lost 90% of your buildings to the enemy
Fully upgraded a turret
Used bezerk powerup 5 times
Nuked the site from orbit 5 times
Used the freeze powerup 5 times
Repaired your buildings 5 times
Used the shield powerup 5 times
Made $5,000 profit from one mission
Made $10,000 profit from one mission
Made $15,000 profit from one mission
Got $10,000 in the bank
Got $25,000 in the bank
Got $50,000 in the bank
New rank: colonel
New rank: brigadier
New rank: major general
New rank: lieutenant general
New rank: general
New rank: field marshal
Defeated 2 Xmas Ultrayetis
Defeated 3 Xmas Ultrayetis
Defeated 4 Xmas Ultrayetis
Hurrah! Christmas is finally over!