It seems like "Your Highness," the second large-scale project by director David Gordon Green realized/created in tandem with Danny McBride and James Franco, is what happens when the guys from "Pineapple Express" take a time machine back to the middle ages: the costumes get older and so, unfortunately, do the jokes.

This film, coming three years after "Pineapple Express," adds Natalie Portman as a third marquee name, though her screen time is very limited (to be specific, it's limited mostly to a scene of her undressing and diving into a pond).

In terms of narrative, "Your Highness" features McBride as Prince Thadeous, a weed-smoking underachieving misanthrope who lives in the shadow of his older brother Prince Fabious (Franco), heir to their father's throne.

Thadeous generally stays in the castle getting high and abusing his squire Courtney while Fabious comes and goes on valiant quests, but when an evil wizard (Justin Theroux, in the funniest role of the film) kidnaps Fabious' bride-to-be (Zooey Deschanel, in another limited role), Thadeous is forced to leave the castle and accompany Fabious on the quest to recover her.

Unlike "Pineapple Express," this film doesn't attempt to keep up a constant stream of jokes; instead, it moves at a slower pace, waiting for a smaller number of outlandish comic moments (if you see it, you'll know what I mean).

Because of the measured timing of the comedy, there seems to be a lot of empty space in the film. Strangely, this doesn't make watching the film an unpleasant experience; it's as easy to watch as any film I've seen (definitely easier-going than "Pineapple Express"), but overall, it's just not as laugh-out-loud funny as most fans would hope.

The entire humor (and potential success) of the movie is based on the hope of McBride and Ben Best (who both co-wrote) that they can play off the clichés and expectations of a film about knights and castles with their brand of silly and irreverent writing. But dropping modern day curses and colloquialisms in a feigned British accent can only be funny for so long.

McBride and Best succeeded in creating material that would be hilarious in a short film or skit format, but when stretched to feature film length, it starts to feel like different versions of the same joke being told over and over again.

Franco does a fine job as the benign older brother whose transformation from a stoner in "Pineapple Express" to a valiant knight in this film hasn't changed the buddy quality of his acting job. It by no means steals the show—there's not much show to steal—but it works here.

McBride, unfortunately, is best when his character is more extreme and fanatical than he is here. At the beginning, he is a stoner and a slacker, but I would have liked to see him go to the extreme of that role instead of the way he plays it, which is watered down and tame.

Despite its faults, its hard to deter people from seeing this film, since I did like it overall. It's just a shame that this team couldn't bring more originality to a concept that had showed some promise.