An isometric {{platformer}} known in North America as ''[[MarketBasedTitle Sonic 3D Blast]]'', starring Creator/{{Sega}}'s [[Franchise/SonicTheHedgehog three-foot speed demon]], developed by Creator/TravellersTales. The game was released for the [[SegaGenesis Sega Mega Drive/Genesis]] in 1996, and then for the Sega Saturn (to compensate for the cancellation of the game that was supposed to be the Saturn's KillerApp, ''Sonic X-treme'') as well as for the PC in 1997. It was not released in Japan until 1999. The Genesis version was the last brand new Sonic release for that system, and second-last overall, after the 1997 compilation ''Sonic Classics 3-in-1'', though that was previously released in Europe in 1995.

Remember that little blue bird that Franchise/SonicTheHedgehog freed out of robot shells in the [[VideoGame/SonicTheHedgehog original]] [[VideoGame/SonicTheHedgehog2 16-bit]] [[VideoGame/Sonic3AndKnuckles trilogy]], the Flicky? It turns out they reside on Flickies' Island, where they can travel through dimensions via giant rings. Learning about this, Dr. Robotnik has decided to invade the island and trap its inhabitants inside his badnik army, that he can seize the seven Chaos Emeralds and {{take over the world}}.

During his usual [[WalkTheEarth nomadic routine]], Sonic pays a visit to his little pals on Flickies' Island, only to discover they've all been imprisoned in badnik shells. Now, our true blue hero must free his friends and stop Robotnik once again.

As noted above, ''Sonic 3D'' is an [[IsometricProjection isometric]] platformer (with nifty pre-rendered 3D sprites), but that's not the only difference in gameplay. Beating an act is not done by reaching the goal as soon as you can; instead, you have to collect a set of five flickies and bring them to a giant ring; there are usually 2-3 giant rings, and once you successfully deposit each set , you beat the act. The only acts exempt from flicky collect-a-thons are boss acts and an act near the end of the game which plays like a classic Sonic stage.

The Saturn version somewhat rectifies the control issues by offering the analog pad as an alternative to the D-Pad, has a CD-quality soundtrack composed by Richard Jacques, additional graphical effects such as fog and water effects, and a polygonal special stage; but it lacks a save game feature (despite being on a system with a memory card-esque feature) and has [[LoadsandLoadsofLoading unusually long loading times]]. The PC version includes Jacques' soundtrack and a save game feature, but lacks some of the Saturn version's other features such as the polygonal special stage and a few graphical enhancements.

Not to be confused with ''VideoGame/SonicBlast'' for the GameGear, though the games were marketed together in commercials
!! This game provides examples of:

* AlliterativeName: All of the zone names.
** With the exception of Gene Gadget Zone, which uses two different "G" sounds (/dʒ/ and /ɡ/).
* ComicBookAdaptation: ArchieComics published a 48-page special featuring a story based on the game's plot, while Fleetway's ''Comicbook/SonicTheComic'' did a very loose adaptation in issues 104-106.
* ConveyorBeltODoom: The setting for the Gene Gadget Zone boss.
* EternalEngine: Gene Gadget Zone and Panic Puppet Zone.
* [[GreenHillZone Green Grove Zone]]
* InCaseOfBossFightBreakGlass: All of the end of level battles with Robotnik until Panic Puppet Act 3, where flashing lights become the new target due to not being able to hit his cockpit directly (you hit the torso of the TrueFinalBoss if you can reach his level).
* {{Leitmotif}}: In the Saturn/PC version, Robotnik's normal theme is remixed into something more epic and sinister for the final boss music. It also makes a brief cameo in the BadEnding.
* LethalLavaLand: Volcano Valley Zone, complete with leaping fireballs and collapsing stone bridges.
* MultipleEndings: Didn't get all the Emeralds? Well then you get the BadEnding, which alludes to Robotnik returning. Get them all? Then you gain access to The Final Fight, which is pretty self explanatory, and if you beat it, you get the GoodEnding.
* OurFounder: In Panic Puppet Act 2, Sonic has to reach the top of a giant Robotnik statue through his nose. The boss fight for the stage takes place inside the statue.
* PointOfNoReturn: The final non-boss act of the game, Panic Puppet Act 2, is a straight Sonic stage with no Flickies, and several points exist in the stage to prevent Sonic backtracking, but the most notable one is at the end of the stage, where you cross several plates that fall below you. After the second one, you're left with no choice but to enter the pipe in Robotnik's nose, which ends the stage and takes you to Panic Puppet Act 3, a three-phase boss fight against three separate Big Arm machines (if you have all the Chaos Emeralds, the Final Fight boss, which is in its own stage, follows Panic Puppet Act 3.)
* RecurringRiff: The Saturn/PC soundtrack incorporates the title theme melody into nearly every single track in the game.
* SlippySlideyIceWorld: Diamond Dust Zone
* SpiritualSuccessor: To the ''VideoGame/{{Flicky}}'' arcade game.
* TrueFinalBoss: The Final Fight, the [[FinalBoss Final]] BossBattle is available by beating the game with all the Chaos Emeralds, beating this boss is needed to get the GoodEnding.
* UnexpectedGameplayChange: The entire game involves killing badniks to free Flickies. But then Panic Puppet comes. Act 1 has you freeing them in pods. Act 2 lacks them entirely, being a traditional Point A to Point B stage. The manual [[HandWave handwaves]] it by saying that Robotnik hasn't had time to put them in the badniks yet as Sonic got there sooner than expected.