I think the Farrellys have bitten off more than they could chew, but that’s actually to their credit. The inciting incident here is pretty cool, in a gleefuly disgusting way: Bill Murray takes that mayo-slavered, salt covered hard boiled egg out of the mouth of the monkey that stole it from him, and off the faeces-flecked ground onto which it has fallen. Then he eats it. Onto animation, and this unsuccessful but laudable mix of public service announcement, school science program and gross out comedy. The Farrellys try to pull that gross stuff back to a PG level, though they may be too thoroughly vulgar to tell the difference. What they lack in strategy they make up for in sincerity (cf. Shallow Hal, Stuck on You). They’re trying, and I’m not sure there’s that much harm in the occasional, properly banked and balanced Chaucerian foray.
As for the movie itself, there are fun and interesting things all over the place. Those Molly Shannon incidents are in very poor taste, and they are pretty funny. The Murray character’s general unacceptableness is also funny, though it starts to get implausible, and then plain silly. Mr. Fishburne is pretty good, as well as the animation and distribution of his character. I should say that Chris Rock is an acquired taste that I have not acquired. The sentimental Dad/daughter story, as well as the burgeoning romance between Osmosis and Leah, didn’t work for me at all. They win some, they lose some. See it, maybe.