Street Fighters Cammy and Charlie Nash are both playable characters in the spin-off shooter Cannon Spike (2000), named after one of Cammy's attacks and bringing together in one title a number of characters from different Capcom series. Furthermore, two unmasked incarnations of Vega, known as 'Fallen Balrog' (the game uses his Japanese name) and 'Revenger Balrog' appear as boss characters bearing a pronounced resemblance to the musician Marilyn Manson.
Hugo's manager and former member of Metro City's Mad-Gear gang is Poison. The alterations and censorship that her character underwent during localisation for non-Japanese markets of Final Fight set in motion the bewildering speculation that has surrounded her sexuality ever since. To simplify: Poison was conceived as a female thug in Japan but concerns about reactions from North American audiences about fighting women resulted in her character being revised as a transsexual. In the international ports for Super Nintendo the concealment went one stage further with the Poison and Roxy characters being swapped for male characters, Billy and Sid. Debate persists over whether Poison should be considered female, a pre-op or post-op transsexual, or indeed something else. Street Fighter IV's producer Yoshinori Ono seemed to clarify the matter when asked about it in an interview:
Let's set the record straight: In North America, Poison is officially a post-op transsexual. But in Japan, she simply tucks her business away to look female.
However, in the artbook for Street Fighter × Tekken (2012) Akiman added his own two cents:
I think of the North American Poison as a transsexual and the Japanese Poison as a woman.
Adoor on the white building situated at the far right of M. Bison's World Warrior stage is revealed using the coin-op's scroll test. During gameplay the scenery is cropped before this point so it is never normally visible. Perhaps this building is where they store all the replacement heads for the stage's highly precarious and oft-broken statues! As a general note, Complete File: Street Fighter II gives the location of this setting as the Ramayana Temple in Bangkok's Grand Palace.
Street Fighter 2010: The Final Fight (1990) manages to reference Capcom's two most popular series in its title despite bearing no relationship to either! To capitalise on Street Fighter's popularity further, Capcom U.S.A. rewrote the background story for and renamed the protagonist from the Japanese version of Street Fighter 2010 for the American release. Kevin Straker was repackaged as Ken from the original Street Fighter game, now a cybernetically enhanced scientist (!) and retired from martial-arts. Besides these narrative changes the gameplay itself is identical, being an incredibly difficult, side-scrolling action-platform game for the NES.
E. Honda's Street Fighter II stage contains a detail exclusive to SNES ports of World Warrior and Hyper Fighting (i.e. Turbo), namely, a paper lantern on the left-side of the baths. This isn't present in the Genesis/Megadrive Special Champion Edition nor any of the arcade versions of Street Fighter II (with the sole exception of Hyper Street Fighter II: The Anniversary Edition). Finally, it's missing in all versions of Super, including the SNES version, GBA's Revival and HD Remix.
Once certain conditions are met, a 'mech' version of Akuma is playable in Cyberbots: Full Metal Madness (1994) a fighting game where the player chooses both a pilot and a mech to do battle with. The mech's name is G-13EX / Zero Akuma. Confusingly, Cyber-Akuma is a human character sharing a similar moveset with the mech and is the final boss in the crossover game Marvel Super Heroes Vs. Street Fighter (1997). Cyber-Akuma is easily identifiable from his appearances in the Street Fighter series proper by his bionic arm, the work of the X-Men villain Apocalypse.
Entering the classic 'Konami code' (↑, ↑, ↓, ↓, ←, →, ←, →, MP, LP) as player-2 during the attract mode's demo fight in arcade World Warrior causes twelve sets of numbers to pop up. Each set refers to the following: (1) Unknown (2) The number of coins put in the left hand slot (3) Unknown (4) The number of coins put in the right hand slot (5) The number of times Ryu has been used (6) Likewise E. Honda (7) Blanka (8) Guile (9) Ken (10) Chun-Li (11) Zangief (12) Dhalsim. These numbers would be highly useful to Capcom in gauging the popularity of each character. The code is expanded in Champion Edition to include the four boss characters.