What does "uneven talent" mean?

...

Tolkien was an Oxford scholar of languages and literature, a man intimately familiar with Norse and Anglo-Saxon mythological texts in the original languages, who wanted to create a mythology for England and the English (Tolkien discounted Arthuriana as real mythology, on the grounds of its historical and especially religious entanglements with the real world). He was also a devout Roman Catholic.

Lucas, by contrast, is a filmmaker of decidedly uneven talent and some passing familiarity with mythic archetypes absorbed from Joseph Campbell; a religious indifferentist who has always viewed the Star Wars films as popcorn movies for children. And so they are, though like The Wizard of Oz they make an indelible impression on young viewers that endures into adulthood; and, for many adults, they still have the power, despite their flaws, to reach the child within us.

...

excerpt from "An American mythology: Why Star Wars still matters" (http://decentfilms.com/articles/starwars)

Hi, I'm a foreign learner of English.

I've got a phrase beyond my comprehension.

In the above passage, does "uneven" mean "extraordinary", or "not continuous"?

Thank you in advance.