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