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