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