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.
Visit every beach in Gaia.
Obtain the Ultima Weapon.
Summon the eidolon Bahamut.
Receive a Very Good Omen from a color fortune.
Summon Eidolons 50 times.
Summon the eidolon Ifrit.
Receive 10 rewards from Queen Stella.
Obtain the complete set of Genji armor.
Locate all hidden treasures on the world map.
Summon the eidolon Leviathan.
Summon the eidolon Odin.
Summon the eidolon Carbuncle.
Summon the eidolon Atomos.
Summon the eidolon Madeen.
Summon the eidolon Shiva.
Obtain an airship.
Win 10 items at the Treno Auction House.
Form a party with four male characters.
Cause Moguo to have a tantrum.
Obtain the Tiger Racket.
Obtain the Whale Whisker.
Obtain Athlete Queen.
Summon the eidolon Phoenix.
Use Black Magic spells 100 times.
Summon the eidolon Fenrir.
Summon the eidolon Ramuh.
Free Kuppo from a wall in Fossil Roo.
Synthesize 10 items.
Guide all the residents of Cleyra to safety.
Use the Steal command 50 times.
Defeat 100 enemies.
Win 10 Tetra Master matches.(Certain NPCs can be re-challenged to increase your win count after progressing through the game.)
Enter Trance for the first time.
Have the nobles demand an encore.
Win a Tetra Master match.
Synthesize 30 items.
Use White Magic spells 200 times.
Use Blue Magic spells 100 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.
Raise your chocobo's beak level to 99.
Repair the machine at Mognet Central.
Obtain a bottle of Superslick.
Successfully catch 99 frogs.
Successfully catch a golden frog.
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.
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.
Attain level 99 with at least one character.
Obtain Madain's Ring via mining.
Beat the Nero Brothers' shuffling game nine times in a row.
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.
Use the Defend command 50 times.
Form a party with Quina Quen and three female 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 Ark.
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.
Defeat Maliris, the Guardian of Fire.
Defeat Tiamat, the Guardian of Wind.
Defeat Kraken, the Guardian of Water.
Defeat Lich, the Guardian of Earth.