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