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