Ok, i am not trying to say that this film is good, because it definitely isn't. However, to call it the worst comedy of the 90's is going a bit far, which many critics did. This movie is basically just an extension of The Tom Green Show only it was a little more unedited because he was no longer restricted by the censorship of networks. This resulted in many disgusting things happening in the movie and well, I didn't like those either.
The story is just dumb and not terribly important as every scene is just a setup for one of Tom Green's skits that really have no bearing on the show. Tom plays Gordy Brody, a slacker kid in his mid twenties who is a talented animator but has no other real ambition in life. This brings about the ire of his father who is played by the immensely-much-more-talented-than-the-rest-of-the-cast Rip Torn (who also has an awesome, although almost certainly fake, name.)
In order to appreciate this film I think you need to understand that it is just the Tom Green Show but longer. The story is not important and the comedy is extremely juvenile such as various nonsensical skits that I really enjoyed such as when Gordy briefly makes his dad proud by asking if he can borrow one of his suits to go apply for jobs but then just spends the entire day playing "The Backwards Man"
I can walk backwards fast as you can!
or when Gordy tries to tap into his musically creative side by creating this modern art musical piece I like to call "Daddy would you like some Sausage"
The movie was a box office flop and some critics who probably take themselves entirely too seriously called it "one of the worst movies ever made." That was a bit harsh I think.
I think you would have to appreciate his show and the fact that Tom kind of looks and acts like Beeker from The Muppet Show to like this movie. Well, i did and I do. The movie barely broke even at the box office but went on to sell millions of copies on DVD. Tom Green never wrote or directed anything ever again.