You don't boil the wort because of the extract (it's already pasteurized by the maker), you boil the wort to isomerize the oils in the hops. If you boiled for less time than the recipe instructed, your beer may be significantly less bitter (might be sweet) than intended.
What was the recipe/time? We can give you a good idea of what your results would be. If you boiled for 45 minutes instead of 60, for example, you may have more hops flavor with less bitterness.