The Adventures of Rocky & Bullwinkle is one of those movies that throws gag after gag (some of them self-referential) at you, hoping a few will connect. Unlike films such as There's Something About Mary or Scary Movie, most of the gags are clean and generally bad puns that will either make you groan or howl with laughter. But overall, I'd argue most people won't enjoy them since they will be considered too clever or too cheesy.
Rocky (voiced by June Foray) and Bullwinkle (voiced by Keith Scott) are in a subversive cartoon land, after their TV show was retired in 1964. However, their efforts are again needed thwart their arch enemies from the TV show, Natasha (Rene Russo, with a great Russian accent), Boris (Jason Alexander), and Fearless Leader (Robert DeNiro in an over-the-top performance) who have resurrected themselves into the real world in the year 2000. The three villains plan to take over the world after hypnotising everyone by transmitting garbage over the television (now I see what the ploy of all the talk shows and shows like Survivor and The Real World is). Aiding them is FBI Agent Karen Sympathy (Piper Perabo), a big fan of the Rocky & Bullwinkle. Together, they must undertake a road trip to Fearless Leader's headquarters to stop him, but not before many detours and adventures.
Even though there is a lot of humour packed in the film, a lot of the gags and puns are indeed painful. The acting is very good, and the most positive aspect of the film is that it is clear that the actors are enjoying themselves. Piper Perabo, who plays the spunky FBI agent, is extremely cute. (I can't wait to see her in Coyote Ugly.) There are several cameos (including Whoopi Goldberg, John Goodman, Janeane Garafalo, and Billy Crystal) which are fun in and of themselves.
I'd recommend skipping this film unless you're really a Rocky and Bullwinkle fan, in which case you should wait for it to come out on video.