Actually, the original Street Fighter only had two playable characters - Ryu and Ken - and Ken was pretty much just the 2 Player Ryu color - you couldn't "pick" Ken unless you jumped in a game or played on the 2 Player side.
Other than the two kinds of button setups, the game could be set up where you picked which country you wanted to fight in next. One setup let you pick between Japan or USA, then it automatically sent you to the other countries after that. Another setup let you pick from all of them (Japan, USA, England or China) sending you automatically to Thailand after you beat those fighters.
2 fighters per country, some recognizable: Mike in the USA was essentially "Balrog" in SF2, Gen from the Alpha series was in China, Birdie and Eagle (from the Alpha series) were in England (though Birdie was a tall, white English punk as opposed to the bulky black dude in the Alpha games), and Adon and Sagat were in Thailand. Sagat was the last guy.
The game is okay for the time. It's nowhere near as playable as any of the Street Fighter games since. The special moves are deadly, but really, really hard to pull off - if you do, though, a fireball can take off a third of an enemy's life, a dragon punch nearly kills them on the spot, and connecting with multiple hurricane kick blows will KO an opponent too.