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