I guess the other reviewers are disappointed by extra goodies that were, or were not, included on the DVD. This is not an expensive disk so I would not expect much, and for that matter, what else could there be? This isn't Lawrence of Arabia! It IS a funny movie with a lot of wit and charm.
I think Duchovny is making a statement simply by accepting a role in a movie that takes a silly approach to the notion of an alien species coming to earth, after having taken it all so darn seriously for years in the X files. He's saying: Lighten up! And if you approach this movie with that in mind, you'll have a gas.
The rest of the casting is creative and effective, with Orlando Jones working well in comic/dramatic tandem with Duchovny, and the wonderful Julianne Moore taking a comic turn as a klutzy but brainy (and of course, beautiful) scientist. The movie pokes gentle fun at the educational establishment, at the military, at politicians, and just about everybody in between, while keeping viewers involved in a storyline that has enough surprises in it to sustain interest -- even among those who somehow miss the humor and overlook the romantic subplot.
If you're expecting Close Encounters of the Third Kind, this is NOT it. If you just want to sit back with a goofy, fun movie that happens to have a strong science-fiction element, and have a bunch of laughs along the way, this is it.