Gogo's stats are all-around poor. They have the worst Strength and the second-worst Speed and Magic after Cyan, and the second-worst Stamina after Strago. Their others are subpar as well. Gogo's low stats are exacerbated by their inability to equip espers, preventing them from receiving stat bonuses.
Gogo's equipment draw is almost identical to Strago and Relm. Gogo can equip rods, maces, and some daggers for weapons, and universal shields, robes, and some light armor. Gogo joins equipped with a Mythril Knife, Mythril Shield, Plumed Hat, and a Mythril Vest. Their ultimate weapon is the Scorpion Tail.
Gogo's inability to equip espers means they rely on stat boosts from equipment to compensate. Their equipment draw thus inclines them to be used as a mage, as the best weapon for stat boosts beyond their ultimate weapon is the Magus Rod, which gives +7 Magic, and the Circlet and Magus Robe also provide good Magic boosts; by contrast, Gogo has no weapons or body armor that boost their Strength. Together Gogo reaches +16 Magic for a more respectable total of 42, which, while far below what most of the player's other spellcasters can achieve, is still a significant boost over the base 26. Beyond stat boosts Gogo's equipment options are lackluster, and their main elemental defenses will have to come from their shield.
In the Game Boy Advance and subsequent releases, Gogo cannot equip the Merit Award. Even so, in the Super NES and PlayStation Anthology releases, usage of the Merit Award does not greatly improve Gogo's viability. The Circlet and Magus Robe give +4 and +5 Magic, respectively; the Merit Award does not afford Gogo usage of any armor that offers a higher boost, save for the Behemoth Suit, which only gives one extra point. While the Merit Award would give Gogo more options to be built as a physical character, the Merit Award could be given to any other character and whatever build the player might use for Gogo, that character could do it better. The one notable exception is the famous "Wind God Gau" combination, which Gau cannot do in the Anthology release due to being unable to equip the Merit Award, but Gogo still can.
Gogo's primary ability is Mimic, where they copy the ability last used by a party member. They can copy any spell, Lore, and esper summon without consuming MP, and mimicking item use or the Throw command will not reduce inventory stock. Mimicking Gil Toss still consumes gil, and mimicking Rage or Dance will cause Gogo to enter the same Berserk-like state that Gau and Mog do. If Mog stumbles when attempting to Dance, Gogo may succeed in their attempt. A successful Dance changes the battle background to match the Dance's terrain, so if Mog succeeded and Gogo mimicks him, they will succeed too because the background is now the Dance's native terrain. The exception to this is battles where the battle background does not change as a result of Dance, particularly the final bosses—in these battles even if Mog's Dance succeeds, Gogo's attempt to mimic it may cause them to stumble.
Gogo cannot mimic Desperation Attacks. If Gogo attempts to mimic a command they cannot copy, or uses Mimic when no other party members have taken an action, they will use a normal Attack command. Gogo can mimic a previously mimicked command again, so long as no other character has acted after Gogo's previous action. This allows Gogo to summon espers indefinitely by continuously mimicking.
Aside from the Mimic command, Gogo can equip up to three command abilities usable by other party members, done through the Status menu. They cannot equip Terra's Trance, and if the party did not wait for Shadow when escaping the Floating Continent, the Throw command will not be usable. Also, if Mog never joined the party in the World of Balance, the Dance command will be unavailable until he joins them in the World of Ruin. If Gogo equips a relic that changes a character's ability, such as the Brigand's Glove that changes Steal to Mug, that ability will be changed for Gogo as well. When equipping the Magic command, Gogo will be able to use any spell that has been learned by at least one other member of the active party.
If through glitching or hacking the player has temporary playable characters in their party when they have access to Gogo, Gogo can access those characters' unique abilities as well, including Pray, Possess, and Shock. If a party member is given the dummied Summon command, Gogo can equip it. Depending on the situation, these abilities may be added at the end of the list of available commands where they will be blank or will replace an existing command, but they will become visible once equipped on Gogo.
Because of how this mechanic works, when fighting in the Cultists' Tower or in the Dreamscape when the party is riding Magitek Armor, Gogo must equip the Attack command to have access to the Magic and Magitek commands. The Rage command will become the Magic command in the Cultists' Tower, but will not become Magitek when riding Magitek Armor.
This variety of abilities affords Gogo a lot of utility, able to act as a less-powerful copy of a party member if the player needs two of them, such as two characters to use Runic in a battle against magic-users, or to have access to any ability the player may need for a specific purpose. For general purpose, Magic, Lore and Blitz are good choices due to Gogo being built as a mage. Magic and Lore allow Gogo to be a back-up and utility spellcaster with an array of spells, and Blitz allows them to use Phantom Rush, which with proper Magic-boosting equipment can deal several thousand damage in spite of Gogo's poor base stats.
Gogo's Desperation Attack is Punishing Meteor that deals magical damage to one enemy. Gogo can trigger Punishing Meteor either by the normal Attack command, or by Mimicing another party member's Attack. If Gogo uses Mimic when no other party member has taken an action, or attempts to Mimic a command they cannot copy, the attack they use cannot trigger Punishing Meteor, but both cases have exceptions; in the first case, Mimicing again after using Mimic once when no one else has acted can trigger Punishing Meteor the second time, and it can also trigger if Gogo attempts to Mimic another party member's Desperation Attack. In all of these cases, Gogo must still be at critical health to trigger Punishing Meteor and there is still a 1/16 chance of it occurring, even when attempting to Mimic another Desperation Attack.
Gogo is recruited in the World of Ruin. On Triangle Island, a monster called the Zone Eater will swallow the party members one by one. When all party members are swallowed, the party will awaken in the Zone Eater's Belly. At the end of the cave, they will find Gogo, who will join the party when spoken to.
If a party member summons Ragnarok to use Metamorphose to turn an enemy into an item, if it fails, Gogo can continuously mimic the summoning until it works, as long as no other character takes action. This makes item farming with Ragnarok much easier and reliable, giving the player access to many rare and powerful items that come in limited supply other than from metamorphosing enemies.
Gogo is a good choice as a fighter for Dragon's Neck Coliseum. Because any action a character could potentially perform may be used at random in coliseum fights, the player can ensure Gogo is locked into a much smaller ability pool and make them more reliable. Giving them nothing but the Attack command with the Genji Glove and the Master's Scroll gives Gogo the potential to attack eight times and they can do nothing else.
Gogo can make the best use of the Imp equipment. A party member under Imp status cannot cast magic except for the Imp spell, but in the Coliseum may still waste turns trying to cast other spells. Gogo does not have this problem, so equipping them with the Attack command and the Dragoon Boots and Dragon Horn relics ensures they can do nothing but Jump attacks, and with the Imp equipment on them Gogo will be very powerful and deal triple damage when Jumping.
The player can manipulate Gogo's actions if using the Tools command by selling all Tools but the ones the player wants Gogo to use (all Tools can be re-acquired elsewhere, either purchased in Figaro Castle or stolen from enemies in Kefka's Tower).