Carl Reiner has a long and storied career, but he may always be best known as Alan Brady on the Dick Van Dyke Show. His manic, monomaniacal Alan Brady was one of the most brilliant characters in sit-com history; the episode where Laura reveals that Alan is bald on national TV may be the funniest sit-com episode ever filmed.
All that being said, this animated effort only captures the faint echoes of the brilliance of this character. Maybe if 'The Larry Sanders Show' had never aired (or hell, even 'My Favorite Year'), this would be considered biting satire. As it is, it's just too slow to work. First of all, it misses a live audience, and the timing is all off. Secondly, the 3-D animation style used has very little energy to it. It's almost like watching the effect of Tylenol PM on adults. This needed a much more zany and somewhat less structured animation style in order to capture the energy of Alan Brady ... certainly not Bill Plympton, but something of that kind of kinetic energy.
As it is, it plays a bit like an old Catskills comedian who is working ten years past his natural retirement date. It has its moments, but Carl Reiner is not past his retirement date yet (see Ocean's Eleven), and this should have been done better in order to capture his genius. I gave it a 5 for a couple of laughs.