Here is the full list of all 48 Clash of the Titans achievements worth 1,000 gamerscore.
Chapter 1: Clear "On the Home Front".
Chapter 2: Clear "Departures".
Chapter 3: Clear "Calibos!".
Chapter 4: Clear "Into the Fire".
Chapter 5: Clear "Face Your Destiny".
Chapter 6: Clear "Scales".
Chapter 7: Clear "The Gate Opens".
Chapter 8: Clear "A Human's Strength".
Chapter 9: Clear "Disillusionment".
Chapter 10: Clear "CLASH OF THE TITANS".
Collect all Sub Weapons in one category.
Pick up one Sub Weapon for each category.
Collect all Sub Weapons.
Reinforce one Sub Weapon.
Completely reinforce one Sub Weapon.
Completely reinforce all Sub Weapons in one category.
Completely reinforce all Sub Weapons.
Successfully perform a Perfect Sub Weapon Seize.
Successfully perform Perfect Sub Weapon Seize three times on one enemy.
Successfully perform a Perfect Sub Weapon Seize three times on one boss.
Defeat 100 enemies with Soul Seize.
Defeat 10 enemies at once with Chain Seize.
Complete all quests.
Destroy enemy parts or protective gear 300 times.
Perform an attack with each of the main weapon skills.
Collect all Gifts.
Perform 30 hits in 7 seconds using a dual-wield attack.
Send 5 enemies flying with one Hammer attack.
Defeat 5 enemies at once with one Axe attack.
Defeat 10 enemies in quick succession with one Bow attack.
Defeat 10 enemies at once with one Wing attack.
Stun 3 enemies at the same time using the Tail attack.
Use a "Healing Core" 5 times to recover the health of a dying support character.
Activate a "Dark Blade" Underworld Core attack and successfully connect 50 times consecutively.
Use a "Flame Core" attack to defeat each type of undead monster, except undead bosses.
Defend 100 enemy attacks using a Barrier.
Use the "Spirit of Argos" to take down 5 enemies at once.
Using the Battle Song on Perseus, destroy a part of the "Skeleton King".
Play 2P Mode for the first time.
In 2P Mode, have a support character perform a Sub Weapon Seize.
Destroy the heads of 20 giant animated statues.
Hit an enemy 20 times while it is in the air.
Pierce a cyclops' weak point with a Bow.
Defeat 20 skeletons who are preparing to throw skulls.
Destroy all parts of the Scorpioch.
Clear "Mating Season" with the ability "Erosion of the Abyss" set.
Obtain S Rank in all Main Quest and Challenge Quests.