The Plumbers are an interstellar police force, using the Omnitrix as a badge symbol?
Kevin is anything other than a total sociopath? What happened to his powers?
Gwen's magic now works in a totally different way than before?
Alien Force is filled with little continuity errors, some larger than others. The only way that I can personally reconcile this with Ben 10 is to declare this an alternate universe continuation. I certainly can not call this a direct sequel of the earlier show.
I do not recommend this show, and the question begs to be asked. What were the people in Man of Action thinking when they created this show?