Keroro Gunso: Meromero Battle Royale (ケロロ軍曹 メロメロバトルロイヤル?) is a Japanese game for PlayStation 2 based on the anime and manga series Sgt. Frog.
- Keroro - Slow but powerful main Keronian character of the series and Sergeant/Leader of the Keroro Platoon. Keroro uses cleaning tools, and a parody of God Gundam's shining finger attack in his combos. Keroro's special attack has him building a gundam. If he is hit in the process he straps dynamite all over himself, and sacrifices himself and close by opponents for the sake of his late gundam. He will do this multiple times if his with a multiple attack. If he is not attacked, he gains a power boost.
- Giroro – Keroro and Dororo's powerful childhood friend and the Corporal/Second in Command of the Keroro Platoon. He uses his gun to smack around his enemies in his combos, and fires it too. Giroro's combo makes him go ballistic, and shoot a heavy forward barrage.
- Tamama – The youngest, Powerful, Private Second Class of Keroro Platoon. He uses his fists in all of his attacks, except "Tamama Impact" Tamama jumps into the air, and throws a giant jealousy ball to the ground in his special attack.
- Kururu – The smartest, creepiest, and Sergeant Major of the Keroro Platoon. Is slow, and uses his inventions to fight. Kururu finishes his combos by growing bigger temporarily (a parody of how Mario grows by eating a super mushroom). He can use his headphones to daze or put his enemies to sleep. For his special attack, Kururu uses his computer to summon a black hole that sucks up opponents.
- Dororo – The swiftest, most emotional, ninja, and Lance Corporal of the Keroro Platoon and childhood friend of Keroro and Giroro. He attacks with his blade. His special attack has him do a quick forward slice on his opponent in front of him.
- Fuyuki Hinata – The 12-year-old main human character and Keroro's partner. He attacks with flailing arms, and physical attacks. Fuyuki's special attack makes him enraged, and maul opponents behind a dark screen. He can only do this if the opponent is close in front of him.
- Natsumi Hinata – Fuyuki's powerful 14-year-old sister and the love interest and partner of Giroro. She fights with her bare knuckles like Tamama, and Fuyuki. Natsumi's special attack causes her to unleash a powerful combo on an opponent in front of her
- Momoka Nishizawa – Fuyuki's multi-billionaire and multi-personality lover and Tamama's 12 Year Old partner. She lets her inner self do the fighting. Momoka can summon her butler, Paul to shortly assist her in battle. Her special attack summons a bolt of lightning to hit her and nearby opponents. Momoka then splits into two temporarily to boost the power of her combos.
- Mutsumi Saburo – Natsumi's love interest, Giroro's love rival, and Kururu's smart 14-year-old partner. He finishes his combos by drawing and summoning a random item to use on the enemy. Mutsumi's Special attack lets him summon the floating objects such as winged rocking horses and Dom heads and uses them to boost his combo's attack power.
- Koyuki Azumaya– Natsumi's best friend and Dororo's kunoichi rescuer, friend, and partner. She uses her blades to fight. Her special attack makes her tear into the enemy with a fast sword combo.
- Aki Hinata The powerful yet kind mother of Fuyuki and Natsumi. She can be unlocked by completing the story mode for all human characters. She is very powerful in the game as in the series. Aki's special attack makes her perform a high uppercut on an enemy.
- Angol Mois The female Angolan lover and niece-figure of Keroro. She is unlocked by completing the story mode for all Keronian characters.