* The Nintendo 3DS version is being co-developed by Sonic Team and Dimps.
* The director of the 3DS version is Tetsu Katano, who directed Sonic and the Black Knight.
* 2D side-scrolling gameplay for both Classic Sonic and Modern Sonic.
* Momentum based gameplay and platforming are fully featured in the Classic Sonic gameplay.
* Modern Sonic plays a lot like the Sonic Rush games and Nintendo DS version of Sonic Colours.
* Nintendo 3DS version will have exclusive stages and boss stages.
* Green Hill Zone will be the only shared stage across all versions.
* Casino Night Zone from Sonic the Hedgehog 2 is confirmed for the Nintendo 3DS version.
* Story has some differences between the console and Nintendo 3DS versions, but will be fundamentally the same.
* Console version will have many characters, but the Nintendo 3DS version will only feature the ones who are integral to the story.
* There is no Wii version. Sonic Team head Takashi Iizuka says this is because “The primary goal for the console versions of Generations was reimagining the series’s classic zones in vivid, high-definition graphics.”
* Sonic the Hedgehog 3‘s Launch Base Zone Big Arm boss fight is in the game, which suggests that stage is also in the game.
* Classic Eggman appears in the above mentioned boss.
* Exclusive to the Nintendo 3DS version are challenged that you can unlock via StreetPass or Play Coins.
* The game also features an exclusive two-player race mode via local wireless connection.
* Modern Sonic stages take advantage of the 3D feature more than the Classic Sonic stages. An example shown and detailed is a part in the Green Hill Zone where Modern Sonic smashes through the bottom of a giant totem pole. The camera then moves to the front of Sonic and lets you see the rest of the pole collapse behind Sonic as he escapes.
* The 3D depth is also highlighted when Modern Sonic occasionally moves between the foreground and the background.
* Jun Senoue and his music team are working on the music for the game.
* Nintendo Power thinks the handful of tracks they’ve heard so far are “fantastic”.
* Special Stages are confirmed and are designed in Sonic Heroes style. As expected, you earn Chaos Emeralds from these stages. Whether or not Super Sonic will be your reward for earning all Chaos Emeralds is unclear right now.

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- 2.5D side-scroller
- new Ninja hero (SEGA wouldn't mention the character's name)
- slice through enemies with katana strikes
- combo attack that juggles enemies in the air
- use an auto-recharging supply of throwing knives
- use fire/water/lightning/shadow magic
- double jumps and evasive slide attacks
- use a grappling hook to reach high places
- wall jump and swing hand-over-hand from the ceiling
- press R to parry enemy attacks
- defend against attacks that come from behind or while you're jumping as well
- game starts off in Oboro Village
- this village is attacked by mysterious enemy forces
- run through burning temples and over collapsing bridges
- face off against enemy ninjas and samurai
- buildings crumble in the background and explosions blast the land
- fight on horseback while rushing through a forest
- horse can trip over fallen trees
- survive an ambush while riding a raft down a river
- climb a waterfall by jumping between falling logs
- explore caves and snow-covered mountains
- battle a female warrior who can disappear in a puff of black smoke
- all details mentioned above are just from the first level
- fight on the back of a moving jet
- fight a giant cyborg megalodon shark
- 3D ninja star throwing mini-game
- unlockable bonus content that you get through completing specific in-game challenges
- save your level playthroughs and share with other players
- StreetPass compatibility

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