Here is the full list of all 85 Final Fantasy IX achievements. It takes around 80-100 hours to unlock all of the achievements on Windows.
Obtain Excalibur II.
Win 100 Tetra Master matches. (Certain NPCs can be re-challenged to increase your win count after progressing through the game.)
Have a single character affected by all status ailments. (both beneficial and detrimental).
Obtain 4 moonstones.
Receive certification as a Rank S Treasure Hunter.
Form a party with Quina Quen and three female characters.
Purchase all items available from Stiltzkin.
View 79 Active Time Events.
Activate the Rebirth Flame ability when all party members are incapacitated.
Defeat 10000 enemies.
Use White Magic spells 200 times.
Summon Eidolons 50 times.
Acquire all available support abilities.
Uncover the secret of the Eidolon Wall.
Raise your chocobo's beak level to 99.
Visit every beach in Gaia.
Repair the machine at Mognet Central.
Obtain a bottle of Superslick.
Successfully catch 99 frogs.
Obtain the sacred blade Excalibur.
Correctly answer all the questions in Ragtime Mouse's pop quiz.
Gain the favor of all friendly enemies.
Defeat Ozma.
Receive 10 rewards from Queen Stella.
Obtain the Hammer.
Defeat Behemoth in the Treno weapon shop using Dagger.
Attain level 99 with at least one character.
Win 10 Tetra Master matches.(Certain NPCs can be re-challenged to increase your win count after progressing through the game.)
Enter trance 50 times.
Summon the eidolon Shiva.
Summon the eidolon Ifrit.
Summon the eidolon Atomos.
Summon the eidolon Odin.
Summon the eidolon Leviathan.
Summon the eidolon Bahamut.
Summon the eidolon Ark.
Summon the eidolon Phoenix.
Summon the eidolon Madeen.
Obtain Kain's Lance.
Obtain the Tower.
Obtain the Rune Claws.
Obtain the Angel Flute.
Obtain the Mace of Zeus.
Obtain the Gastro Fork.
Obtain the Ultima Weapon.
Defeat Maliris, the Guardian of Fire.
Defeat Tiamat, the Guardian of Wind.
Defeat Kraken, the Guardian of Water.
Defeat Lich, the Guardian of Earth.
Complete FINAL FANTASY IX.
Play the blackjack minigame.
Defeat 1000 enemies.
Receive 30 back attacks.
Use Blue Magic spells 100 times.
Win 10 items at the Treno Auction House.
Synthesize 30 items.
Obtain the complete set of Genji armor.
Locate all hidden treasures on the world map.
Obtain an airship.
Use Black Magic spells 100 times.
Summon the eidolon Carbuncle.
Obtain the Whale Whisker.
Obtain the Tiger Racket.
Form a party with four male characters.
Obtain a miniature copy of the Prima Vista.
Beat the Nero Brothers' shuffling game nine times in a row.
Obtain Athlete Queen.
Summon the eidolon Fenrir.
Summon the eidolon Ramuh.
Obtain Madain's Ring via mining.
Free Kuppo from a wall in Fossil Roo.
Guide all the residents of Cleyra to safety.
Synthesize 10 items.
Use the Defend command 50 times.
Defeat 100 enemies.
Successfully catch a golden frog.
Win with Vivi during the Festival of the Hunt.
Receive a Very Good Omen from a color fortune.
Use the Steal command 50 times.
Cause Moguo to have a tantrum.
Enter Trance for the first time.
Have the nobles demand an encore.
Jump rope 1000 times without tripping and obtain King of Jump Rope.
Jump rope 100 times without tripping.
Win a Tetra Master match.