Depends on your taste in humor. This movie frequently aims for the low end of crude humor spectrum. (It's too easy to constantly drop the F word for a punchline sometimes.) I was hoping for something along the lines of Monty Python and the Holy Grail, which it isn't. There hasn't been a lot of sword and sorcery comedy done since then.
I did get a several good laughs out of it in spite of things. I have a strange sense of humor though! Can't tell you my favorite line without spoiling it. I've been quoting it for days now...
It's also pushing the envelope of it's R rating in several places. (And there's a lot of nudity, but not from Natalie, just so you know!) Had a PG-13 cut been imposed, it probably wouldn't work at all. Can't say more without major plot spoilage. (Holy Grail is practically a PG film by today's standards.) You're never going to see this on basic cable uncut if at all!
On the plus side, it's got some great FX sequences which seem inspired by some of Ray Harryhausen's films. This almost could have been an interesting tongue in cheek fantasy epic had they not been going for outright comedy. I bet somebody does a fan edit down the road!
It will probably hit the bargain theaters pretty soon, and be on video by late summer.