Sonic Adventure 2: Battle (JP) is remake of the Dreamcast game, Sonic Adventure 2. It comes with the addition of a Multiplayer Mode (Battle) & Game Boy Advance connectivity via the Game Boy Advance to Nintendo GameCube Link Cable. Also, this game introduced Shadow the Hedgehog, the ultimate life form created by Professor Gerald Robotnik, the grandfather of Dr. Eggman, and Rouge the Bat, a Gem-obsessed treasure hunter, both out to steal the Chaos Emeralds for their own reasons with Dr. Eggman.
The game opens up with Eggman attacking one of G.U.N.'s military bases. In that military base he is trying to find a project called the "Ultimate Life Form". When he finds the project he finds Shadow who is the result of that project. The doctor, Shadow, and soon afterwards, Rouge set out to go to the Space Colony A.R.K.. Soon Sonic is captured. Sonic, Tails, and Knuckles set out to beat Dr. Eggman and get the Chaos Emeralds back. On the Space Colony A.R.K. sonic and his friends set out to get different things done. Sonic soon gets blasted into space. But sonic uses Chaos Control to get back to the A.R.K.. Tails and Eggman soon fight each other, after Eggman "killed" Sonic. When Sonic gets back onto the A.R.K. he and Shadow then fight. They then find out Professor Gerald Robotnik's plan to ram the A.R.K. into the Earth. The original Ultimate Life Form, Biolizard, wakes up. Biolizard transforms into FinalHazard, and Sonic and Shadow have to turn Super to defeat FinalHazard.
GameplayIt is very similar to Sonic Adventure. But Tails can no longer be playable without the Tornado (outside of the Chao Garden). There are no hub worlds in Sonic Adventure 2, a level select map is what replaced it. You can play as Sonic , Shadow , Dr. Eggman, Tails, Knuckles, and Rouge the Bat. The characters have new levels only for those characters in the game (unlike Sonic Adventure). Sonic and Shadow's stages are the speed stages. In Sonic and Shadow's stages you are at high speeds going through levels. Tails and Dr. Eggman's stages are the mech characters. Eggman and Tails mostly play the same. And Knuckles and Rouge are treasure hunters. The treasure hunting has been changed in some ways. The Treasure Hunting stages are larger than the ones featured in Sonic Adventure. You can also play the Chao Racing minigame. Once you get all 180 emblems you unlock a recreation of Green Hill Zone. You are usually fighting G.U.N.'s robots or Dr. Eggman's robots throughout both the "Hero" Story and "Dark" Story. There is also a Kart Racing minigame.
You can play many different modes in the game. You can play Kart Racing. There is also a Action Race mode. You play as Sonic, Shadow, Amy, and Metal Sonic in that mode. Some charaters that where not playble in the main story are now playable like Amy Rose , Chao Walker, Dark Chao Walker, Chaos Zero, Tikal and Metal Sonic. All characters are unlocked at the start. There is also Treasure Hunt mode, and Shooting mode in the 2P Mode.
- The green X's in the Crazy Gadget level were turned red, due to its similar appearance to the Xbox's symbol.
- The Dreamcast version had downloadable content, while this version doesn't, though some can be unlocked through other means
- The majority of the appearances of Big the Cat in the Dreamcast version were removed
- Big the Cat is playable instead of the Dark Chao Walker in the Dreamcast Version.
- Tails, Rouge, and Shadow were not intended to be playable originally, which is why they play just like Eggman, Knuckles, and Sonic respectively.