Here is the full list of all 69 Final Fantasy X/X-2 HD Remaster achievements. It takes around 200 hours to unlock all of the achievements on Windows.
View the "Underwater Date" scene
Listen to all of Maechen's stories
Roll the same number on all the Gambler's Dice
Achieve a 99 chain attack
Defeat Trema
Obtain Anima
Use Bribe 30 times
Change dresspheres on Yuna, Rikku, and Paine in one battle
Defeat Zalamander
Obtain Magus Sisters
Defeat Bahamut
Obtain Magical Dances, Vol. II
Complete an episode in Chapter 5
Win a race with a catcher chocobo with a total time of 0:0:0
Complete the ability set for one dress
Catch the Amazing Chocobo
Pass all chocobo training
Get 5 treasure chests during the Chocobo Race at Remiem Temple and win the race
Unlock all slot reels
Reach the 60th floor of Iutycyr Tower and defeat the boss
All party members come together
Use Mix 30 times
Steal successfully with Rikku 200 times
Win a blitzball match in FINAL FANTASY X
Learn the Jecht shot
Clear the Besaid Cloister of Trials
Find 1 Al Bhed Primer
View "Eternal Calm"
Obtain all available FINAL FANTASY X achievements
Win a blitzball tournament
Defeat Yunalesca
Defeat Seymour Omnis
Dodge 200 lightning strikes and obtain the reward
Obtain Yojimbo
Buy every sphere at the Luca Theater
Do 9999 damage or more in a single attack
Spend 100,000 gil or more in bribes
Obtain all Jecht Spheres
Deal 99999 damage with one attack
Complete a Sphere Grid for one character
Learn to use all enemy abilities
Obtain all Aeons
Obtain all Celestial Weapons
Find all 26 Al Bhed Primers
Complete the Sphere Grids for all main characters
Defeat Penance
Defeat Nemesis
Defeat Yu Yevon
Obtain all available FINAL FANTASY X-2 achievements
Obtain one special dress
Help Clasko catch a chocobo by the end of Chapter 3
Defeat YSLS-Zero
Win 10 times at Sphere Break
Learn 5 Blue Bullet skills
Pay off O'aka's debt
Win a blitzball match in FINAL FANTASY X-2
View one complete fiend tale
Open the chest that includes the Ribbon in the Bevelle Underground
Reach the highest level (LVMAX) in Gunner's Gauntlet
Obtain all dresspheres
Complete Shinra's Bestiary
Defeat Vegnagun
Complete 100% of the main story
Reach the 10th floor of Iutycyr Tower
Reach the 20th floor of Iutycyr Tower and defeat the boss
Reach the 40th floor of Iutycyr Tower and defeat the boss
Obtain treasure in the Tonberry area
Reach the 80th floor of Iutycyr Tower and defeat the boss