So I just finished the game and of course, it puts you back before you actually beat the last boss after you've beaten him.
That annoys me but still none the less it's a pretty good game, I did thoroughly enjoy the first two and finished them with ease.

A question I have is, can you get back to the start, where the Cabin is to deliver the Roc feather? That's if anyone else has played this game of course.
Wouldn't mind seeing what happens with the soarwing.

from what i read (didnt actually played the game) u cant go back from certain point, so i would assume its impossible to comeback to the start when u finished the game, unless u start a new file

but again i didnt play the game so

Gosh so it was pointless altogether getting the stupid Roc feather if I can't get back to the Cabin... FAIL! haha.

Yeah I beat the game also, and was very angry at the points of no return. i even went as far as sailing around for multiple days (IRL) looking for ways to glitch the game. I reached level 99 at the area before the boss and found out that if you kill the 4 people in the background your party will gain more exp.

There are a few things to do after saving and destroying the last boss. you can visit a old dungeon that was in Golden sun 1 or 2 IDK but its pretty easy to find, a NPC in the town where you get HIMI will tell you.
Next is the whirlwind going around the ocean. It will take you to a badass dungeon, which makes no sense and will confuse you. It is pretty fun

next thing to do is farm the best gears in the game. I made a full crit page with Maramusa the dragon sword for my Amiti, and a crit page for Eoleo. Zol rings will be part of your final build, so will a CRIT ring [only 1]

now the problem with this is I realized I could beat the last boss with the normal iron swords a NPC sells LOL so pretty much the game has NO REPLAY VALUE>

Looks to me they are going to need to make a new one.
Like in Golden Sun 1 and 2 how they had the shaman rod, in the first one you have it all game and then you finally use it in the second game.. So I reckon they are going to need to do something pretty similar to that.
I already went to both of the island's. Got owned at the treasure island one, boss was heaps tough, which means more training for me, not even level 50 yet
But none the less I do like this game, I've been a fan of the Golden Sun games since I played them on a VBA emu.

So I got my team to level 55-56
Got more summons, like from Crossbone Isle etc. Took me long enough but I used the advice by training on the soldiers near the end boss.
I recommend this game to everyone.

But bring on Pokemon White