3D Classics

3D Classics is a label applied to certain remakes of old games for the Nintendo 3DS, with added stereoscopic 3D functionality and updated features while retaining their original art style and graphics. So far, there are two (otherwise unrelated) series: a first-party series of NES/Famicom and arcade games, and a Sega-published, M2-developed set of classic Sega games, mostly from Sega Mega Drive/Genesis and Sega arcade hardware.

The first set of games in the series were developed by Arika and published by Nintendo. These releases were directed by Takao Nakano from the Special-Planning & Development Department of Nintendo. Development on this set of games began in 2009, starting with Namco Bandai Games' Xevious. They underestimated the amount of work required to add stereoscopic 3D to a 2D game, requiring much more work than a simple port. Arika attempted a 3D Classics version of the NES/Famicom game Tennis because the background had perspective, but found it looked unimpressive in 3D while requiring re-coding collision detection almost from scratch.

Games in the series published by Sega are branded as "Sega 3D Classics" and are developed by M2. Many of the Sega 3D Classics are remakes of games that originally used Sega's "Super Scaler" technology, which created a pseudo-3D effect by rapidly rotating and scaling large numbers of sprites.

Some of the Sega 3D Classics provide options that try to emulate the arcade experience, such as option to enable motion controls or show the screen tilt in games like After Burner II and Super Hang-On. 3D Sonic the Hedgehog allows players to switch between the Japanese and international versions of the game. Some Sega 3D Classics introduce new features altogether, such as "Super Dolphin" invincibility mode in Ecco the Dolphin and the Spin Dash in Sonic the Hedgehog (which is a technique originally introduced in Sonic the Hedgehog 2).

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