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