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