Street Fighter, the game that started the 1 on 1 fighting revolution has a lot to answer for, lets take a walk down memory lane.
Street Fighter was the evolution of those basic 1 on 1 fighting games that dominated arcades in the 1980's. Street Fighter had two playable characters, Ryu for 1 player, and Ken for 2 player.
The most unusual aspect of Street Fighter was the fact that there were no buttons but pressure pads. The harder you hit these pads, the harder your onscreen character would attack. This unique idea failed because the pads were easily damaged, new Street Fighter machines were shipped with the now standard 6 button layout.
Street Fighter had all the signature moves that we have now, but they were very hard to pull off. Above we have Ryu performing his hurricane kick.
Woah! A dragon punch! You could not imagine how hard these moves were to do. I played Street Fighter once at Alton Towers and it was very hard indeed. The above picture also shows Gen, who made his re-appearance in the alpha series.
Completing Ryu's special moves, we have the hadoken. Ryu's oppponent is Mike - a boxer. Street Fighter had a good selection of enemies, many of which have appeared in more recent games. Birdie was representing England as was Eagle, Adon was the penultimate boss, with Sagat being the toughest guy you would ever face.
Those of you expecting a fantastic end sequence showing the scarring of Sagats chest will be sorely disappointed as it never happened. Capcom has changed the story of Street Fighter and how Ryu won the tournament.
Ryu finally defeated Sagat with a cheap shot. Ryu was down on the ground after having been pummelled by Sagat, then Sagat reached out to take his hand, knowing that he had won, but Ryu was so obsessed with winning that Satsu no Hadou overtook him and he ripped through and burned Sagat's chest with his Metsu Shoryuken, becoming Evil Ryu for a split moment there. This is an official statement, and probably a retroactive change by Capcom, considering that it wasn't until one of the latest versions of Street Fighter 2 that Satsu no Hadou even freaking EXISTED as a concept within Capcom's writers' minds. At any rate, you can also see this in Evil Ryu's ending in SFA3. While Evil Ryu in SFA3 is a what-if character, he temporarily flashbacks about his fight with Sagat in SF1, which is NOT a what-if occurrence (obviously). And you know it's his fight with Sagat in SF1 and not his midboss fight with Sagat in SFA3 because the post-fight dialogue didn't have Sagat acting like his chest just got ripped through with Evil Ryu's Metsu Shoryuken. You can also see this in Adon's SFA2 ending (where Satsu no Hadou is mentioned as the power that Ryu used to defeat Sagat) and in Ryu's SFA2 plotline in general (he's seeking out Akuma to find out more about the Satsu no Hadou because he doesn't know what it is when it overtakes him in defeating Sagat).
When Ryu, now the first Street Fighter World Warrior champion, finally got back from the Street Fighter 1 tournament, he wanted to ask Gouken what happened to him. However, he found Gouken killed as well as his daughter missing (Author note: Gouken having a daughter is a fact that Capcom seems to have forgotten about by now and thus will probably never resurface. You can only find out about his daughter in REALLY old Street Fighter official sources). Ken, however, had seen the end of the battle that happened. It was Akuma, Gouken's brother, that killed Gouken. Sensing Akuma's chi, Ryu then embarked on a journey to find Akuma (because Ryu still needs to find out what happened to himself when he beat Sagat, and for vengeance).