Compared to other RPG games of which Atelier shares common traits, Marie and the rest of the series focus less on combat and heroically saving the world and more on the mundane, accessory tasks you may do on your adventures. Combat plays second fiddle to the gathering and crafting process, the game functions as if Persona's social links and every MMO crafting profession had a child.

Marie is the first in this series, released in 1997 on Playstation in Japanese only. Since remade in 2023 with a new art style and expanded options, like unlimited mode. We play as Marlone (Marie for short), who is completely inept at her studies at the Royal Academy of Magic. Given an Atelier (Alchemy Shop) as an alternative method to prove herself, there are 5 years to complete a "high-quality" item to prove Marie has what it takes to be a Mage and Alchemist.

Now that the fluffy introduction is out of the way, I am going to recommend two references to assist you with your 100%. These two posts definitely go into far greater depth than I do, perhaps too much so.
PSNProfiles Guide by AlchemistWer & Dsr8002[psnprofiles.com]
Blog post by S. Cusack[eruciform.com]

Alchemaster
Unlock all achievements.

Memory Lane
Completed 100% of the event list.

Almost everything you do in Atelier Marie revolves around the Event List Menu. It catalogs all goals, storylines and social interactions. It is the actual hardest achievement due to it requiring all events being seen on one save file, which is impossible without going into NG+. So to achieve this the first goal is a normal timed run with the Legendary Pair ending. I recommend saving as close to the first and fifteenth of every month and check the event log vigorously before doing anything that will take multiple days. There are several missable events that take place on specific days in specific years that aren't available in unlimited mode. The menu itself is a little confusing at first blush but generally, it's ordered by story line and pressing Triangle / Y to view specific characters is very helpful.

The Legendary Pair
Entered the Martial Tournament with Schea.

Do this one first on a normal/timed playthrough. It's fairly simple, get both Marie and Schea to level 50 and complete the quest line to cure Schea's health problems in Year 3. Schea's health quest requires 600 reputation and 3000 knowledge, which shouldn't be a problem by the time it comes around if you are working toward Memory Lane. Save the ending in a new slot, and do so everytime you get one.

Once you have finished your first play and are ready for NG+, it's time to speedrun being a failure. Equipment items transfer over if they are equipped on a character, they vanish if in inventory/stock. Start NG+ and restart a normal/timed run. Do not continue. Then sleep and faff about till five years have passed. There is no achievement for the failure ending but it's an event for Memory Lane. You can also do the summer market events on 6/28 if you are missing any. Save in a new slot.

The remaining ending will be achieved in a very specific order and you must take precautionary steps to avoid getting a higher tier ending. Cure Schea's illness but you should avoid leveling Schea, at all if possible. Keep Marie's level below 50 till the appropriate ending. Do not 100% the crafting list, the common recommendation is to avoid making Stardust since it isn't an ingredient for anything else, and avoid the Aroma Materia for the Philosopher Stone till required. Kit out everyone again before hitting the next NG+.

I ... Passed?
Managed to graduate somehow.

This will be your third ending, start NG+ off your failure ending and restart an unlimited playthrough. Do the bare minimum of what you have to to make a level 6+ item. The Elixir to cure Schea is level-7 and counts for this requirement. Additionally, work on getting missable events and books/key items. This is really a second full playthrough but take a minimalist stance on it. Increase reputation and knowledge but keep Marie's level low. Use Navy Fairies making Megacrafts to fund everything and if you have need of additional funds for fairy labor, you can go to the Mine, avoid combat and gather Glasen Ore. Sell it to the Weapon Store for 420 each. Make it to Exam day. Save in a new slot and continue, not restart.

Philosopher
Become a professor at the Academy.

To achieve this end you must make the Philosopher Stone. Which requires the flower found during the eclipse on 6/18. Spirit's Tear from completing Schea's illness quest. Slay the dragon for a Dragon Tongue. Create the Aroma Materia. All this will require 600 reputation and 3000 knowledge. Since we continue from the previous ending, you should have everything but the Aroma. Go to the bulletin board once you have the Stone then continue your game.

Local Hero
Saved Salburg from disaster.

Defeat Magician Faren and complete Schea's illness quest and remain below level 50. Do not complete the crafting list. Climb the tower, blow the boss back to hell. Bulletin board and save, continue.

Living Legend
Left Schea to embark on your own journey.

Get to level 50+ and cure Schea. Keep her below level 50, don't use her in your party at all.

Researcher
Pursue a career as a researcher.

Complete the Crafting and Item portion of the Guide to 100%. This includes all weapons/armor, tree nuts from the midnight scream events, books, tools, and decorations from Flair. You should have most or even all of this by now and ideally just be missing Statdust or whatever item you avoided. Hit the bulletin board once you've got it all. As long as no events are ???, gray is ok, you should also get Memory Lane.

Barrel Roll
Inspected a barrel.

There are barrels in the Atelier, Weapon Shop and Tavern.

Window Shopper
Purchased absolutely nothing.

Weapon Shop or Academy Shop, buy menu and close.

ZZZ
Rested for three or more days in a row.

Save, sleep, quickload.

A Royal Welcome
Gained entry to the Royal Castle.

Starting in Year 2, you must complete the event chain Two Men 1 once, and Two Men 2 twice. Go to the castle and be turned away by the knight with the blue armor and Warcraft pauldrons. Then do the King's birthday event on 5/23. Ten+ days later, return to the castle and the man from the above events will give you a pass key item. Go to the castle again.

Hit The Books
Read every reference.

Books come from three locations. The Academy store, the library and hidden library which requires higher and higher amounts up to 600 Reputation and 3000 Knowledge. Events from Mu, Kugel, Weapon Shop Owner, Flair/Der Himmel event line and Schea's illness event line.

Interior Design
Acquire five different designs.

Dio, the Tavern owner has a pink haired daughter named Flair. She rarely takes over for Dio and you must speak to her atleast twice. From Year 2 on she will randomly open a stall on the rightside of the town square. Each season she sells a new decoration set for the Atelier. The fifth will appear after getting the first four.

Busybody
Listened to every rumor.

Rumors are marked with a red/white exclamation mark on townsfolk or sold by Dio, the Tavern owner. Some are tips or lore bites, others will unlock Event chains. There is no surefire way to force a rumor to show up, you just have to check the fast travel menu for exclamations, especially near upcoming calendar events. But raising Reputation and Knowledge will cause more to appear. Also, you need the castle pass to get rumors from the king.

Bosom Buddies
Reached max friendship with all allies.

There are ten allies and friendship maximum is 100. Keep in mind that the summer market on 6/28 requires six characters to be lowest friend to achieve their event. Also, each character's event chains require friendship level thresholds to trigger. If you just want to speedrun max friendship with someone, you earn 1 point for each adventure. So go to the Nearby Forest then return to town, repeat. Additionally, some characters become unavailable in a time run after a specific date.

Alchemy 101
Synthesized an item for the first time.

Look At Me Go!
Synthesized thirty items.

Fairytale
Met a fairy for the first time.

10 days after creating a rank-3+ item. For fastest results, purchase Alchemy III from the Academy store. Craft Mystica Leaves out of Mystica, Puniball, Green Neutralizer to trigger the event. A fairy will knock on the door of the Atelier and give you a charm key item so you can recruit fairies from their forest.

Prodigy
Synthesized a rank-7 item.

Vroom Broom
Synthesized a Living Broom.

Talk to Flair twice to trigger the Der Himmel event chain in Year 2. Read the Soul Arts book from the Academy library to learn Living Rope. You also need to craft Elixir, Megabomb, Drink of Life to trigger the Philosopher Stone recipe event. This let's you get the last book, Dornie's Theory which reveals the recipe for Living Broom made from living rope, magic herb, bamboo, holy water.

Item Collector
Reached 100% completion of the item guide.

All gathered ingredients, crafted items, weapons/armor, and key items. Just the first two tabs of the Guide and a step for the Researcher ending.

I Got This
Achieved level 50.

Know-It-All
Achieved knowledge over 3000.

Household Name
Achieved reputation over 800.

Handywoman
Completed 50 quests.

Requests from the Tavern and friends.

Hair Today ...
Completed the Weapon Shop Master's quest.

Event chain for the shop owner in Year 2. Follow the events and craft the item required. After accepting the quest you will need the Mysteries book from the Academy library.

Bestest Friends
Cure Schea's illness.

As mentioned several times above. Year 3 and requires 600 reputation and 3000 knowledge to get the books to make the item.

Hard Worker
Completed all of Ingrid's assignments.

Every six months you will receive a task from Ingrid, the silver haired teacher. All ten of them are easy and the requirements may be met before you even get the task. In order, they are:

• Adventure with 4 different allies
  
• Visit 5 gathering areas
  
• Collect 25 kinds of ingredients
  
• Purchase all references at the Academy
  
• Raise knowledge to 3000+
  
• Synthesis 30 kinds of items
  
• Raise reputation to 300+
  
• Raise Marie's level to 35+
  
• Visit 10 or more areas
  
• Synthesize a rank-6+ item
  

Miss Moneybags
Amassed 99,999 coins.

Sell Glasen Ore to the Weapon Shop, megacrafts to the Academy Shop and do quests in the Tavern.

First Adventure
Traveled outside for the first time.

Mountaineer
Reached Mount Wieland

Fairy Godmother
Hired seven fairies at once.

10 days after creating a rank-3+ item and getting the Fairytale achievement; You can use 9 days to travel to the Fairy woods to recruit one Fairy per trip. Seven is the max and the Navy fairies are the best but most expensive.

World Tripper
Traveled to 10 different destinations.

Master Gatherer
Gathered ingredients 100 times.

Battle Fever
Achieved victory in 50 battles.

Bag Of Tricks
Used Marie's special to strengthen an item.

At level 35, Marie gets a new ability to power up items. Press Triangle / Y then Square / X.

Monster Hunter
Reached 100% completion of the enemy guide.

Some monsters only appear on route to a destination. Most are found in their respective zones , the Tower being a big target. As far as I know: the Bandit, Turban Bandit, Bandit Leader and Bandit Chief are missable. If you do not collect them before defeating the Bandit Chief or the first year ending. Additionally, the rarest enemy is a gold puni which is found only on the way to the Waterfalls.

Bandit Boss
Defeated Bandit Chief

During Year 1, you will get rumors about a cave full of bandits. Travel there and defeat him.

Wind Spirit
Defeated Wirbel

Found in the back of the third screen of Strudel Falls. Possibly random appearance or only during Spring/Summer. I'm unsure as she wasn't present once when I went looking during Winter.

Fire And Fury
Defeated Flammpfeil

After hearing rumors of a Dragon in the mountains. He is found at the top of Mount Weiland but has event lines involving a missable companion recruited late in year 2 after doing the Two Men event chain. Wait till that character is available and you have progressed the related events.

Lord Of Demons
Defeated Faren

Found in Erfolg Tower after four waves of enemies. Required for the Local Hero ending as well as being related to an event chain involving a missable companion recruited during Year 2.

Mini Maestro
Won a gold medal in six different mini games.

The minigames are found in an extra menu from the main menu. They are only available if you did the game during a playthrough and have gotten atleast one ending save.

Windfall
Won a gold medal in Apple Rush.

Unlocked by collecting a Ripe Apple in the North screen of Medea Forest during Autumn/Winter.

It Was THIS Big
Won a gold medal in Golden Salmon Search

Unlocked by finding a Golden Salmon in Strudel Falls during Spring/Summer. Wirbel will also drop one. When you try to leave to return to town, the game will trigger.

Punipunipuni
Won a gold medal in Punpuni Hammer

Unlocked from a random road encounter on the way to Strudel Falls.

Ratcatcher
Won a gold medal in Catch Those Rats

Unlocked by crafting Charicheese in the Atelier.

Naptime
Won a gold medal in Name Collector

Unlocked by crafting a Time Slate in the Atelier.

Treasure Hunter
Won a gold medal in Treasure Hunt.

Unlocked by beating four enemy waves and Magician Faren in Erfolg Tower, Then climbing the tower again before the "secret" boss spawns 60 days later. This event is repeatable as long as you climb the tower when the boss is dead.