The French language uses articles - definite and indefinite - all the time, unlike in English. Indeed, the singular, feminin article La is needed.

Starfix is a magazine geared towards hardcore fans, and I think they chose an English title to make it sound cool. Afterall, can you think of one science fiction film from France since the days of Méliès?

Although, it should be said that the French are using La Guerre des Etoiles less and less and using the English Star Wars more and more. I could be wrong, but I think the French title is used to refer to the 77 film only.