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