Super Smash Bros. for Nintendo 3DS and Wii U

Super Smash Bros. for Nintendo 3DS and Super Smash Bros. for Wii U (colloquially named Super Smash Bros. 4 and abbreviated as SSB4) are the upcoming fourth installments of the Super Smash Bros. series being developed for the Nintendo 3DS and Wii U respectively. It is a sequel to Super Smash Bros. Brawl, in which Sonic made his debut in the series. Like previous games in the series, they are being developed by Sora Ltd. along with Namco Bandai and directed by Sora Ltd. founder Masahiro Sakurai. On June 2012, it was announced that Sora Ltd. is working alongside Namco Bandai Games in developing the games.

Development
Prior to the official announcement and trailers in 2013, Super Smash Bros. for Nintendo 3DS and Wii U was announced in the E3 (Electronic Entertainment Expo) during 2011, however, the title name was not known and no information regarding to the game was announced, as Masahiro Sakurai was still developing Kid Icarus: Uprising. He also stated that a Nintendo 3DS version of SSB4 will be released as well, have more changes in SSB4, and also have dual support for the 3DS and the Wii U. Sakurai also wanted to make the gameplay experience better than its predecessors. And after months of development, it was confirmed by Nintendo that the first screenshots and a trailer of SSB4 will be show during a 2013 E3 edition of Nintendo Direct.

In the Nintendo Direct of E3 2013, Mega Man from the Mega Man series by Capcom was announced as the guest character of the series (and the third third-Party Character, after Sonic and Solid Snake, to be in a Super Smash Bros. game). They also announced newer characters such as the Villager from the Animal Crossing series and the Wii Fit Trainer from Wii Fit. During a Q&A with Masahiro Sakurai, during the 2013 E3, it was revealed that both games may not come out at the same time. It was also revealed previous characters may not make it due to the Nintendo 3DS's space limitations.

In a Nintendo Direct on 1 October 2013, Sonic the Hedgehog was confirmed to be a playable character,  making this his second appearance in the series since Super Smash Bros. Brawl. Windy Hill from Sonic Lost World is also recognized to be playable as his home stage in the Wii U version, however, there is no announcement if that level will be on the Nintendo 3DS version as Sonic Lost World was released for the handheld system as well. Sonic retains his ability to transform into Super Sonic as his Final Smash and he now shouts "Super Sonic Style". Shadow the Hedgehog will once again appear as an Assist Trophy using Chaos Control to slow down the user's opponents just as he did in Super Smash Bros. Brawl. Eggrobos will appear as enemies on the 3DS-exclusive mode Smash Run.

Console Differences and Similarities
Due to the hardware capabilities along with other such hardware used in the 3DS and Wii U, there is many differences with almost everything in the game. Note that the differences shown below may change as the game comes to its final development.
 * The game will be released separately instead of the same day so more time is done to make the game as complete as possible. The 3DS version will be released in 3 October 2014 and the Wii U version will be released by the Winter of 2014.
 * All of the playable characters in the game will be on both of the consoles. However, all of the stages will be different on both versions of the game.
 * Playable characters will run at 60 frames per second (fps) on the 3DS version, even in stereoscopic 3D, while some of the Assist Trophies and Pokémon (such as Meowth) in the 3DS Version will run at 30 fps. All fighters will run smoothly so it shouldn't affect gameplay.
 * Both versions will offer online multiplayer by Wi-Fi, though it is recommended for Wii U users to use a Wii U LAN Adapter for smoother online play.
 * There are two musical pieces on a stage on the 3DS version while the Wii U version brings back "My Music" from Super Smash Bros. Brawl, which allows players to set how often a song will play on each stage.
 * Smash Run, which is a battle mode where it allows up to four players to search in a dungeon with power-ups, is a 3DS exclusive and will not be on the Wii U version.
 * The Wii U Version will support Amiibo figurines which will give individual character data and stats for the figurine and it can be exchanged to and from a figurine. This is not included in the 3DS version.

Trivia

 * Super Smash Bros. 4 will be the first Super Smash Bros. game to be released on a handheld system under the name Super Smash Bros. for Nintendo 3DS, as well as the first Super Smash Bros. game to be released on two systems.
 * Many fans speculated that Super Smash Bros. for 3DS and Wii U was the third and final video game for the Nintendo-Sega partnership along with Sonic Lost World and Mario & Sonic at the Sochi 2014 Olympic Winter Games. However, it was revealed by an interview with Aaron Webber that the third Sega-Nintendo Sonic the Hedgehog video game is something "completely different than before." A Facebook comment by the official Sonic the Hedgehog page also confirms that Super Smash Bros. for Nintendo 3DS/Wii U is not the third game from the Nintendo-Sega partnership. It was later revealed that the third game is Sonic Boom: Rise of Lyric/Sonic Boom: Shattered Crystal.
 * Sonic was revealed in October 2013, the same month that he was confirmed to be in Super Smash Bros. Brawl in 2007.
 * Classic Sonic in his original 16-bit form can be seen on Pac-Man's promotional poster.
 * Coincidentally, Sonic has encountered each of the company's mascots in some form before Super Smash Bros. for Nintendo 3DS and Wii U:
 * Mario and Sonic met through the video game Mario & Sonic at the Olympic Games in 2007.
 * Archie Comics made a crossover between the Sonic and Mega Man franchises a few months before Sonic's confirmation, known as Sonic & Mega Man: Worlds Collide in 2013.
 * Sonic and Pac-Man appeared in the Disney movie Wreck-It Ralph in 2012 and were guests at Fix-It Felix Jr.'s party.
 * The deluxe editions of Sonic & Mega Man: Worlds Collide depicts Sonic, Shadow, and Mega Man in a Super Smash Bros.-like cover.