Battle Mode

The Lobby as it exists in Golden Sun: The Lost Age.

Battle Mode is a feature in both Golden Sun and The Lost Age available as soon as a main game save file is created. It allows solo players to battle a never-ending gauntlet of monsters and bosses from each game's respective campaign, and it also allows for multiplayer party-on-party combat between players with their own hardware and copies of the game.

It is presented as a context-free space existing separately from the setting of the games themselves, with the characters fighting either monsters or each other in a colosseum similar to the one seen in the first game's Colosso competitions.

All equipment, Djinn, and consumable items possessed by the party in the save file used to initiate Battle Mode can be used without fear that the items will be lost when the campaign is resumed. This is a purely optional mode without any rewards for doing well.

Lobby

In both games' versions of the Battle Mode, you can walk around the Lobby and speak with every party member other than your main character whom you have recruited into your party in the main game. You can also talk to various other generic NPCs, as well as use the Sanctum-based services of the Great Healer. Using Psynergy or saving is disallowed while you are in the lobby; on the other hand, battle records are automatically saved by the female NPC at the counter.

In Golden Sun: The Lost Age in particular, holding a shoulder button while talking to the blonde female NPC at the lower-left corner of the lobby brings up a hidden feature allowing you to listen to all tracks of the music featured in both GBA Golden Sun titles. During a campaign in progress, each piece of music you have come across will be unlocked for this menu the next time the save file is used to enter Battle Mode with. If a Clear Saved Data file is used to enter battle mode, all 90+ tracks will be unlocked automatically, including a lot of otherwise unused tracks that played only in the first Golden Sun.

Monster Battle mode

The Monster Battle feature allows you to battle any previously defeated monster formation in the save file with statistical buffs corresponding to your own party's current levels.

If you talk to the female NPC at the counter while there is no other copy of your respective game ready and waiting on another system connected with a Game Link Cable, the Monster Battle mode is forced on you once you step into the white circle.

Monster Battle plays out as a series of inescapable battles against any of the monster formations you have already encountered in the current game file; like a true endurance mode, your streak ends once your party either loses a battle or elects to quit an ongoing run. While battles against Djinn are not part of the pool of possible battles to win, boss battles notably are. The size of your streak is recorded in the Battle Lobby for that file once you fall in a battle. Any items used in these battles will automatically be returned to the party at this time.

All enemies that appear in the Monster Battle mode dynamically increase their statistics in proportion to your party's level, and these bonuses increase further as more battles are won in a row. If the game file being used is a Hard Mode replay, the Hard Mode bonuses of +50% enemy HP and +25% Attack and Defense will also apply to all enemies at all stages. Note that any full-blown bosses that may randomly appear will receive all of these statistical increases the way the lesser enemies do, which can result in enormous spikes in difficulty that might seem arbitrary. On the other hand, any enemy that is introduced mid-battle, such as an enemy summoned by a "looks for allies" skill or a summoned member of the Ball enemy line, will not receive any of these buffs.

In an extreme case of difficulty spiking, it is plausible for an endgame-level party in The Lost Age that has completed all the content in the main game to randomly encounter the most overwhelming optional boss in the game, Dullahan, in an even stronger-than-normal version; this is essentially an automatic game-over. There is also nothing stopping the party from being matched against the same souped-up boss multiple times in a row.

If you are interested in scoring as high a streak as possible in this mode using a thoroughly developed endgame-level party, it would be prudent to use a game file in which none of the game's optional bosses have been defeated yet: Dullahan, Star Magician, Valukar, and Sentinel. Other bosses that may appear in the mode should become manageable at least for a while if you are using powerful class and gear setups such as either Isaac or Felix producing near-guaranteed Unleashes every turn with the Sol Blade, or multiple party members being in the Ronin class using Quick Strike.

Link Battle mode

If two cartridges of Golden Sun are linked using a Game Link Cable, the Link Battle option becomes available; the same holds true if two The Lost Age cartridges are in systems that are linked, though it is not possible for a Golden Sun cart to link to a The Lost Age cart. In this mode, both players' parties fight each other directly. However, each player is restricted to the use of only the three leftmost party members, and a time limit is set on each player's turn, with characters who have not been given orders in time being forced to defend by default. All of your Link Battle wins will be displayed on the wall.

Party quotes in The Lost Age

When spoken to in the The Lost Age version of the Lobby, the seven Adepts other than Felix will make different remarks depending on who is currently in the front party (i.e. one of the first four party members):

In Golden Sun: The Lost Age

Jenna If Jenna and Felix are both included among the first four party members: "Hey, I'll do my best if you do yours!" If Jenna is not one of the first four party members, but Felix is: "OK, I'll be waiting right here. Do your best, and hurry back." If Felix is not one of the first four party members: (Visibly angry) "Wait, I say I'll fight, and then you back out of it? What's that all about?" Sheba If Sheba and Felix are both included among the first four party members: "You don't even want to try? I'll show you my power." If Sheba is not one of the first four party members, but Felix is: "Don't you want me with you anymore, Felix?" If Felix is not one of the first four party members: "Good luck, Felix! If you want me, you know where to find me." Piers If Piers and Felix are both included among the first four party members: "All right, Felix, we'll do it together!" If Piers is not one of the first four party members, but Felix is: "Are you trying to tell me something, Felix?" If Felix is not one of the first four party members: "So it's just me. Is that all right? I'm a little nervous." Isaac If Isaac and Felix are both among the first four party members: "It's our turn. Let's go, Felix." If Isaac is not one of the first four party members, but Felix is: "OK, we're set, Felix. But remember, you're calling the shots, all right?" If Felix is not one of the first four party members: "I'll fight enough for both of us..." Garet If Garet and Felix are both included among the first four party members: "Hey, Felix, I'm all set to show you what I've got." If Garet is not one of the first four party members, but Felix is: "What? I have to take a break? Why do I have to do that?" If Felix is not one of the first four party members: "If you don't want to fight, that's fine. We'll do better without you, no problem." If spoken to in Golden Sun: "I can't wait, Isaac! Let's go get 'em!" Ivan If Ivan and Felix are both included among the first four party members: "If you want me to fight, I'll do it, but don't expect anything amazing from me." If Ivan is not one of the first four party members, but Felix is: "There's something really sad about being told to stay behind." If Felix is not one of the first four party members: "Huh? No way! Please fill in for me!" If spoken to in Golden Sun: "Yes, I'll always help Isaac in battle!" Mia If Mia is among the first four party members: "I'll do the best I can!" If Mia is not one of the first four party members: "That's fine, I could use some rest anyway." If spoken to in Golden Sun: "I'll do my best."

Trivia

The fast-paced music heard during the Link Battle mode's multiplayer component can only be heard in full in this mode by players of the first Golden Sun; in the main game, it is only allowed to play for ten seconds or so as the scripted "boulder escape" sequence takes place in Altin Peak. In The Lost Age, however, solo players can listen to it in full during the Double Up phase of Super Lucky Dice.