It was a forward jumping kick, with fire covering Ryu and Ken's feet as they surged towards their enemy. The vocal sound clip was removed, but the fire graphics were still present in the retail arcade version's rom data.

It was present in the demo version of Street Fighter I, and replaced by the Hurricane Kick in the final retail arcade version.

Before the emblematic "Hurricane Kick", Ryu and Ken were supposed to have another third attack : which one ?

Ryu had red hair, gloves and shoes in Street Fighter I. But in the demo version, he had light, tawny wristless gloves, along with the shoes he since lost along his way.

Ryu has emblematic dark brown hair and red gloves. Which color were these in the demo version of Street Fighter I ?

Ken, alongside Ryu, had a headband in the original demo version of Street Fighter I, yet lost it - alongside his pair of shoes - in between.

Ken had one in the Alpha series, and in the demo version of Street Fighter I, but lost it in the retail version and onwards. What is it ?

Sounds unlikely, but this was the initial Hadoken scream in the International version of Street Fighter I, while the japanese original had the "Hadoken" sound clip. This was never translated again since, even in the Movie game, where the Shoryuken attack was translated "Dragon Punch".

The legendary "Hadoken" fireball attack was initially translated from japanese in the retail version of Street Fighter I. What did Ryu and Ken scream upon launching it ?

This was the initial plan, but it greatly slowed down the gameplay and in turn, the machine's throughput. Hence the switch to two out of three.

The retail version of Street Fighter I introduced the "Two out of three rounds" rule for designating the winner of a bout. But what was it in the demo version of Street Fighter I ?

The reason for the imput change isn't known.

(If the arrows don't appear, please warn me in the comments section after the quiz.)

What was the initial input combination for the Shoryuken ?

Found only three days before the game release, this typo was unfixable through tile edition, something the engine itself couldn't do. Akiman had to copy the tile containing the "o" of "World", then insert one of Guile's tiles in order to fix the cover. This all was corrected on the SNES port.

Street Fighter II developer Akira Yasuda discovered a typo on the Street Fighter II Title Screen three days prior to the game's release, back in 1991. What was it ?

The Hienshu (Chun-Li's backhead knee upon jumping above her opponent) was introduced in Champion Edition, yet was present in the data files of The World Warrior. It made it through to test phase, yet was removed out of balance concerns.

Which of these four emblematic Chun-Li's moves, despite being present in the "World Warrior" data, has been removed prior to release ?

These sprung from the dock bollards visible in the release version, and ran unto the screen's edge, hinting at the presence of another boat right behind the player's viewpoints.

Which large item was featured on Ken's stage during Street Fighter II development, before being backgrounded out in the release version ?

This is the name of the street, as mentioned on a hidden road sign also backgrounded on the release version.

(Yup, it has a name)

What's the name of this street ?

(it was removed for unknown reasons, but was still present in the sound files of the arcade release)

Besides Chun-Li, which World Warrior initially had a specific K.O. sound during the development of The World Warrior ?

These included special move imputs, countering strategies, advice pertaining to getting the best out of a dizzied opponent... The reason for their removal upon internationalization is also unknown.

it was placed below the portait and the countdown panel, and was kept into all versions up to Super Turbo.

The japanese version of Street Fighter II's Continue screen featured something extra, which was removed from the International version. What ?

There's no additional info on her, but an additional unused theme that sounds like it could be her ending theme.

Super Street Fighter II features 16 characters... and 17 names in the data files : What was the 17th name ?

Even though Dee Jay also had a renamed move, Cammy White indeed got the palm in terms of unused data !

One of the New Challengers has renamed special moves, unused animation sprites and even a muted line of dialogue in its ending in the arcade version of Super Street Fighter II. Which one ?

Present in early promo material, this subtitle was later broought back in Capcom Arcade Stadium... then into Street Fighter 6. Grand Master Challenge was the subtitle of the Japanese version.

(Yup, it had one... ^^)

As for "The World Warrior", "Hyper Fighting" and "The New Challengers" : what was the subtitle of "Super Street Fighter II Turbo"'s International version ?

Akuma's electrocut sprite featured him with a red outline instead of a yellow one, along with reddish bones and his top-knot's shadow.

Akuma had a specific sprite exclusive to him during the development of Super Turbo, yet ended up borrowing the same as Ryu and Ken in the final product. Which sprite ?

The sprite animation, despite being present in the retail Japanese version of Super Turbo, was removed in the International port, where only the first and last sprites are shown. No info on why.

Fall down after getting Shungoku Satsu-ed

Which one of these actions could Bison do in the Japanese version of Super Street Fighter II Turbo, yet no longer in the international version ?

written "我が拳に敵なし". He had none in the International version.

What was Akuma's win quote in the japanese retail version of Super Street Fighter II Turbo ?

Blanka appears in the movie and the console ports of the video game, while both Akuma & Fei-Long appear in the video game only.

Which of these four characters never appears in Street Fighter : The Movie, nor the eponymous game ?

In hopes of rivaling Mortal Kombat, developers created a secret codes menu similar to Mortal Kombat's Kombat Kodes, including red herrings such as "Akuma found", "Fatalities done", etc. . One was created for each of these, except Scorpion.

Which of these four characters isn't mentioned in the red herrings menu within "Street Fighter : The Movie" ?

The background of Street Fighter Alpha's character select screen was blue and green. What color was it in Street Fighter Zero, the original Japanese port of Alpha ?

In Zero, Sodom had quotes such as "Do more swim a sand" instead of "Dōmo Suimasen" , or "Oh at early !" instead of "Ōatari !!", which were completely scrapped following a change of character during the game's export worldwide.

Which character went from confidently speaking wrong Japanese to a blood-lusting madman upon translating Street Fighter Zero to Street Fighter Alpha ?

A far cry back from the first Street Fighter and it's "country select" feature, this feature was intended, as prove a sprite in the data with this text. This feature would only see the light of the arcade neons five years later, with "Street Fighter III Third Strike".

What feature, initially intended as a response to several Neo Geo rival titles, was ultimately scrapped from Street Fighter Alpha II ?

Although Text-based, these character endings further expanded the characters' lore to a point of meaningfulness. These texts appeared on superimposition over the final win pose, and before the game credits, furthering their backstories and giving most a backbone reason to fight.

What feature, sorely lacking in the international release of Street Fighter EX, was in fact present in the original Japanese release ?

Yup. Two of Holger's moves were present in the release Japanese version of Street FIghter EX, but were censored in Niigata & Odawara prefectures of Japan, as well as the International release.

This bloke had two moves that were censored in the international release of Street Fighter EX, and even were censored in some parts of Japan : Which moves ?

An autosave feature was present in the Japanese version, yet was removed on international release. Reasons unknown.

What feature was present in the Japanese version of Street Fighter EX + Alpha (the PlayStation port of Street Fighter EX), yet removed from the International version ?

Sharing his spot on the CharSel screen with Necro, Hugo was graphically unfinished in "New Generation", had little to no attacks and always faced Gill. He was probably kept hidden due to time constraints.

Which character, officially debuting in the "Second Impact" update, was in fact present and selectable in the arcade release of Street Fighter III : New Generation ?

As revealed by Third Strike's main planner, Hidetoshi Ishizawa, during an interview to the Capcom Secret File. This also revealed that Remy was the last SFIII character they got out of the drawing board, while Chun-Li the hardest to actually give life to.

Which character, initially set to debut in "Second Impact", ended up cut from it and only appear in "Third Strike" ?

Released Sept. 22, 2008, this demo featured no music, no SFX, no voice clips : not a single sound whichsoever.

What was the weird peculiarity of the Prototype demo version of Street Fighter IV ?

These two lines said "The answer lies... at the heart of battle" and "Now rise up !" and were both voiced in English as well as Japanese. It's not clear why they both got left out altogether.

Which character, present in the base roster of Street Fighter V, had two lines of voiced dialogue go completely unused ?

You do know Street Fighter videogame series, but do you know them well ? Do you know what other players don't ? Do you know what Capcom tried to keep secret ?
This quiz covers deep iceberg secrets from most of the franchise's main titles : cut content, planned then scrapped characters, hidden sound files : Basically everyhting the discs, cartridges and cabines kept hidden within themselves, and the most of which aren't even told on surface-level YouTube videos.
Just like Street FIghter II's True Ending, this is the ultimate Street Fighter Quiz, power ★★★★★★★★★★.