This movie's just weird. It's not that faithful to the book, the humor's not that funny and sometimes just random, the sets aren't really impressive, the plot's pretty primitive and kinda dumb, the characters seem cliche while The Cat is mostly annoying, and the ending's very anti-climactic. I'm also very puzzled about who the intended audience is: Not little children because of the adult-humor, not teens because of the premise and toddler humor, not Seuss-fans because of the differentiation from the book, and certainly not non-Seuss-fans. It disappoints in all ways.
But even so, it could be found amusing for some people (particularly younger audiences) and might even garnish at least a laugh. It's not unholy-horrible, just not that good.