I thought it was good, but not great.
First of all the truncating of the joke about the demolition plans was pretty painfull. If they really couldn't aford the extra 30 seconds they should have cut something else out to make room for it.
The shoehorned-in romance subplot was stupid.
The restoration of the earth was stupid. Likewise the way they got out of the mice wanting his brain thing wasn't very good either, though maybe that's because it was impinged upon by the already mentioned romantic subplot.
I wish they'd done a bit more of the first restoring normality scene. They made up for it somewhat with the later jumps, but the first one should have had more than one transformation.
I was really confused about what that planet they went to before Magrathea was, it seemed very random and unexplained to me.
And as long as i seem to be on a thinking about movies trend...
I've been told that before my time, in fact probably at _least_ a half century ago, it was reasonably possible for someone to read every SF story that came out during any given year. Nowdays of course that would be impossible unless you made that your full time job, and quite possibly not even then.
You could however pretty easily see every theatrically released movie pretty easily. (At least if you stuck to domestic releases.) So i've been wondering, how long until technology has advanced enough such that a couple of amateurs could put together a theatrical quality movie in their spare time using a fairly average home PC. ("Theatrical quality" in terms of the visuals, although given some of the stuff released to theatre's theatrical quality acting and story shouldn't be that hard to achieve =)
Presuming that we haven't destroyed ourselves and the megacorps hacen't destroyed our rights before then, i presume there will be the same kind of creative explosion that is currently going on with flash media. So at that point will they actually be competing with the corporate media, or will hollywood have moved on to 3-D full immersion entertainment or some such? If so i wonder how many people will be interested in watching 2D amateur movies and how many will think that's "old people" entertainment.