Golden Sun: The Lost Age Cheats (GameBoy Advance)

Instead of entering a new name for Felix, press SELECT, SELECT, SELECT. This will allow
you to enter new names for other people (Garet, Ivan, Mia). Press UP, DOWN, UP, DOWN,
LEFT, RIGHT, LEFT, RIGHT, UP, RIGHT, DOWN, LEFT, UP, SELECT to enter even more new names.

After beating the game once, use a blank save space to start a new game.  It will then ask
if you want to play in Easy mode.  If you say yes, you will play in Easy mode (duh).  If
you say no, it will ask you if you want to play in Hard mode.

To get the trident you must get all its three pieces. The center prong is on a long snow
covered island with cracked ice. The right prong is on the top of the shirne of the sea
god. The left prong is on the top of the Ankini Ruins.

There are several extra combo summons to be found. With the exception of Azul, you need to
know Teleport from the Mars Lighthouse.

Azul: Treasure Island (defeat Star Magician) 

Dealdus: Yampi Cave (defeat Vakuar) 

Catastrophe: Tropical island (Sentinel)  Note: You must complete trading
process (give baby  turtle to older turtle for ride to spot) first.

Iris: Inside Anemos Sanctum (defeat boss)

To have the Blacksmith in Yallam forge items faster, just enter the sanctum and exit
again. The item will have been forged and ready for you to receive.

Enter the Battle Arena and while holding L + R speak to the girl in the lower left corner
of the room. You can only hear songs that you've heard in-game.