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