Tomichin is an unused character from the Marvel tie-in games whose design, whilst never seen in a finished game, can nevertheless be found in two places. Firstly, unused sprites exist in the data for Marvel vs. Capcom: Clash of Super Heroes (1998) where he was presumably pencilled in as an assist character but never completed. His image and bio also appears earlier, however, in the 'Secret File #13' flyer for Marvel Super Heroes Vs. Street Fighter (1997) suggesting that he was originally intended to be included in this game. His likeness is based on Atsushi Tomita, planner for these early 'versus' games.
The character of Ryu is heavily parodied in Electronic Art's 2007 The Simpsons Game. In the game's sixth stage, entitled 'Enter the Cheatrix', Bart and Lisa have to overcome enemy characters that look exactly like Ryu, with a Simpsons twist of course. A couple of additional references to other Street Fighters come in the form of the karateka's taunts: 'I am not a pacifist like Dhalsim' and 'Prepare for the Thousand Hand Slap!' (an exaggeration of E. Honda's Hundred Hand Slap). As well as sharing Ryu's appearance the characters also perform his trademark Hadoken.
Several of Akuma's sprites are cropped in the finished version of Super Turbo. Furthermore, the complete sprites (with the missing tiles intact) can be found in the game's data. This is odd. The affected sprites are his standing block and far standing hard kick where his topknot is cropped in both and his far standing medium kick where some of the frayed threads of his gi are cropped at the shoulder. And that's not all; an electrocuted/skeleton sprite for Akuma also exists in the data (note the topknot) but this was substituted for Ryu/Ken's skeleton in the final release, which is a shame. And that's not all! There are unused sprites for a Ryu/Ken style Hadoken startup (he uses a bowlegged stance in the finished game), an extra frame for his standing hard kick, two frames intended for his vertical jumping light/medium kicks and, to complete the set, sprites imitating Ken's rolling (kick) throw, which he doesn't possess in-game. And that's still not all! In World Warrior, there is an unused startup frame for the Hurricane Kick for both Ryu and Ken. It was eventually used for 1/60th of a second in Super but only for Ken. Akuma has this same sprite and, like Ryu, it's unseen in-game.
Cody's A-ISM Super in Alpha 3 is a homage to his infinite combo (known as 'shifting') in the original Final Fight. To perform this in Final Fight you hit the opponent twice, turn away and whiff the third hit and then repeat the combo. This works on all enemies, including bosses. The combo is performed automatically for 18 hits in Alpha 3 when executed at Level 3. Taking the homage one step further, Cody's X-ISM super in Alpha 3 essentially turns him into his Final Fight version; he has only one standing attack which can be used to perform his four-hit, uppercut combo from Final Fight. Additionally, all air attacks are replaced with one kick and when the player pushes backwards Cody turns around and walks forward (as in Final Fight) and it cannot be used to block. Thanks to Ryukenden for these details.
Project X Zone is a crossover tactical role-playing game published by Namco Bandai for the Nintendo 3DS, released in 2012. It is a follow up to 2005's Namco × Capcom and, like its predecessor, it features a number of characters from the Street Fighter series. At the player's command as Pair Units are Ryu and Ken, and Chun-Li, who is accompanied by Morrigan from Darkstalkers. Juri Han appears as an assist character (as does Batsu from Rival Schools). Additionally, Street Fighter IV's Seth appears as an enemy character in the game.
The Super Turbo iteration of Thunder Hawk has a stray hitbox for one frame on the recovery of his crouching, medium punch. This means, that for this one frame, it's possible to damage him without apparently touching him. Players who've spent any time fighting T. Hawk in Super Turbo will be latently aware that this happens even if they have no knowledge of why. Curiously this bug doesn't exist in Super so it's manifestation in the sequel is something of a mystery. When the HD Remix of Super Turbo was released the bug was removed, sparing T. Hawk the embarrassment of being punched in the head in thin air, in high definition. Credit to sonichurricane.com's hitbox article for the image here.
Time to get obscure again.... Oto Ranger: Rhythm & Battle! is a Japan-only music/RPG game released for iOS in late 2013. (It also goes by the name Sound Rangers if you're looking to find out more about it.) As well as featuring a wealth of characters from the Mega Man series, the game also hosts cameos from three characters from the cancelled fighting game, Capcom Fighting All-Stars: Code Holder. They are: D.D. ('God of Thunder'), Rook ('Fallen Angel') and Ingrid ('Eternal Goddess'). The latter, of course, joined the cast of Street Fighter in Alpha 3 MAX (2006).