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