All the X-Men movies suffer the same problem, it's like they only focus on Magneto, Xavier, and Wolverine. I remember Azazel but I always forget about Riptide being in the movie so I'll give you that his goons were pretty unmemorable. It's kind of like they scraped the bottom of the barrel for X-Men characters. Or just drew names out of a hat at random. Also the problem with calling it a prequel is the movie takes place in the 1962. Havok is Cyclops' younger brother, yet in Wolverine which I guess takes place during the Vietnam War Cyclops is a teenager. Meaning that Cyclops would be the younger brother and Havok would be the eldest. Also there's no mention of Havok by Cyclops in any of the other films and Mystique never makes reference to being an X-Men or knowing Xavier prior. Beast is the only one eluded to as ever being a member of the X-Men before in X-Men The Last Stand. Also, there's the case of the two Emma Frosts and the small matter of Xavier walking in the 1980s when being crippled in First Class in the 60s.