If you find Street Fighter Alpha 3 overwhelming, then you should try Street Fighter Alpha 2.  18 characters containing some of the most popular characters from the series: Ryu, Ken, Dan, Chun-Li (has her Kikoken fireball, but not her Spinning Bird Kick), Akuma, Sakura, Zangief, Dhalsim, Sagat, and he-plays-just-like-Guile Charlie.  Each character has his/her own ending.