Note that in the early releases of the game there was a bug where achievements would not unlock at all. This bug has been fixed as of version 1.00.48. I managed to get all achievements using this verson.

If you are achievement hunting, try to make sure you are online and connected to Steam!

I recommend using CTRL+F to search for the specific achievement you need help with.

There are 3 types of achievements in Grandia.

• Missable Achievements - These achievements are easy to miss, and may be impossible to backtrack and obtain after progressing the story up to a certain point.
  
• Story Achievements - unmissable as long as you play the game to the end
  
• Grinding Achievements - technically missable, but easy enough to get as long as you have a saved game somewhere before the final boss

If this guide has helped you, please rate it up. :)

I've listed them here chronologically based on how early they begin.

Get your allowance from Mom.
On any day after Justin's duel, talk to Lilly (Justin's mom). Keep telling her she's beautiful and she'll eventually give you some money.

Deliver Francois's letter to Clara.
While you are in Parm, talk to the Old Man in House 2 until he gives you a letter to deliver to Clara. When you reach New Parm, give the letter to Clara, who lives in Mansion 1.

Do a good job swabbing the deck.
Get a good time in the deck cleaning minigame on the Steamer. It should unlock if you get 25 seconds or faster. Remember to just hold the button, not mash it to increase the speed gauge.
Note that in previous versions of the game, this achievement only unlocked on Justin and Sue's first day as apprentice sailors on the Steamer. It did not unlock if you played the minigame on subsequent days. This should have been fixed but to be safe try to do it on the first day.

Found the other stowaway.
After Sue gets caught as a Stowaway, talk to the old man in the Second Class area of the Steamer until he confesses that he is a stowaway as well. After leaving the Steamer, search one of the barrels near it. The old man is hidden in one of them and will give you a reward for your silence.

Collect all 18 Mana Eggs
Arguably the hardest achievement to get, especially if you miss a single egg. Note that you can still spend the eggs for magic or keep them in your stash box. Here are their locations.

• Dropped by Squid King (boss of the Ghost Ship)
  
• Merrill Road
  
• New Parm Church Underground Passage
  
• Rangle Mountains (West)
  
• Rangle Mountains (East)
  
• Dom Ruins (2)
  
• Valley of the Flying Dragons (3)
  
• Valley of the Flying Dragons (4)
  
• Mt. Typhoon (Foot)
  
• Typhoon Tower (1)
  
• Volcano Slope (1)
  
• Petrified Forest (1)
  
• Savanna Wilderness (West)
  
• Savanna Wilderness (East)
  
• Castle of Dreams Dining Hall
  
• Abandoned Laine Village Warp Space (2)
  
• Underground Ruins (4)
  
• Shrine of Alent Garden

For detailed map locations of the eggs, please refer to nJOY's Mana Egg guide[i-njoy.net]

Gadwin has joined the party.
This should have been an unmissable achievement, but some players have reported missing it. I'm still not 100% sure what triggers this achievement, but it should pop up if you do both of these:

1. Make sure to select "Of course! A man-to-man promise!" option the very first chance you get when you meet Gadwin.

2. Talk to Gadwin again after the conversation ends, before leaving the area you meet him in. Special thanks to user Mana Egg for tip 2.

If you did not get the achievement, check you did both of these. Otherwise you'll have to load a previous save. The nearest savepoint before Gadwin is at the start of Flying Dragon Valley (1).

Defeat the Lord's Ghost.
Beat the boss in the bonus dungeon Castle of Dreams which is located in the South Zil Desert. I recommend doing this dungeon before Soldier's Graveyard because it is much smaller. This boss is fast and does a lot of lightning based attacks. I recommend getting the Hurricane Belt and equipping it on Milda for this fight. For a more detailed dungeon guide, see nJOY's guide[i-njoy.net]

Defeat the Kung Fu Master.
This guy is the final boss in the bonus dungeon Soldier's Graveyard, which is located in the North Zil Desert. He is pretty easy to beat if you have high defense as his attacks are all physical. However the dungeon he is located in is pretty big with lots of enemy mobs. For a more detailed dungeon guide, see nJOY's guide[i-njoy.net]

Defeat the Leviathan.
The Leviathan is the final boss in the bonus dungeon Tower of Temptation, which is located in East Savannah. The hard part is reaching him because he is at the top of the hardest dungeon in the game.
Here are some tips for the Tower of Temptation

• Although there is only ONE save point at the start of the dungeon, you can backtrack anytime before Floor 8. Enemies you defeated will remain dead unless your reload or restart the game.
  
• If you are careful to avoid the final boss trapdoor on Floor 8, you can still backtrack while you're exploring Floors 8-9.
  
• Completing Floors 1-4 will unlock shortcut elevators from Floor 1 to 7.
  
• Completing Floors 5-7 will unlock the stairs from Floor 7 to 9.
  
• Bringing anti-Blizzard and anti-Lightning armor is recommended for the final 2 bosses.

For a more detailed dungeon guide, see nJOY's guide[i-njoy.net]

The story achievements are listed here in chronological progression order.

Most of these achievements aren't particularly hard, just time-consuming.