Reuben Fleisher's "Zombieland" has a clever concept at its core that does not crib as much from Edgar Wright's classic comedy "Shaun of the Dead" as I had expected: This film examines the benefits of a zombie invasion. There's lots of great parking, no lines at amusement parks, and the violence against zombies act as a great stress reliever. These segments of "Zombieland" have a gleeful zeal. However, Mr. Fleisher has never directed a film before so he leans heavily on bathroom humor and has a real problem with consistency. As fun as it is, "Zombieland" could have been a little tighter. For a film that only 82 minutes long, that's almost a fatal flaw.

Zombieland was once the United States, before the infection. Now most folks are either the murderous undead or their prey. There are survivor's, such as the young man whose insulated, obsessive-compulsive lifestyle makes him surprisingly prone to survival. As played by the great young actor Jesse Eisenberg, his looks suggest he was second in line when Michael Cera said "no" to this role. But Eisenberg does much for this nervous, no-named character only called "Columbus": He captures the film's ultimate point that loneliness and melancholy can be worse that succumbing to cannibalistic undead. Columbus is joined by "Tallahassee" (Woody Harrelson), another loner whose tough exterior masks emotional distress. There's also Wichita and Little Rock (Emma Stone and Abigail Breslin), two sisters who end up coming along for the ride despite their - and the audience's - initial reluctance. While each character has some form of mistrust and emotional distance, they all bond throughout the film in predictable ways learning that, even in a world overrun with gore and violence, you can still make human connections. While you've seen this before, each actor brings a winning charm to their roles and to the situations.

As far as that script goes, there are some very clever moments in "Zombieland". Columbus' survival tips are practical but the film reminds us of them every time they become relevant. It's a funny running gag. Also funny is "Zombieland"'s capture of the video-game blood lust. There is no anguishing over loved ones turned; this is just good-old fashioned mayhem. There's a peculiar freedom in watching these characters use all sorts of interesting contraptions to stay alive. The gags are too good to give away. In order to enjoy all of this, the audience has to endure a lot of potty jokes. I am not sure why all of this is necessary, except that bathroom jokes play to the most basic, lowest-common denominator of our humor making for an easy laugh. I am sure there are people who can defend it or will justify this type of writing all they want. It's lazy and out-of-place here. Why so many scatological jokes in a comedy about zombies? You've got me...especially when they don't even bother to explore what zombies do when nature calls. I mean, as long as your mind is in the gutter, why not explore something new?

Further, there are quite a few inconsistent themes in "Zombieland". There's a moment where one of the main characters alludes to the "Zombie Kill of the Week" where we are introduced to a new person who, quite simply, has a funny way of killing zombies. But that's the last time the character or concept is ever heard from again. Why was it introduced? Since it was, shouldn't this have been attached to something else going on with the rest of the film? It also seems like Columbus' narration and the use of his rules is done only when the filmmakers seemed to think about. Nothing much annoys me more than a film that introduces a narrator and then simply forgets about it for a long stretch of time. There's also a problem with Wichita and Little Rock as characters in that their motives and intentions seem to shift at the will of the script. These two young actresses are very talented and can only do so much to keep these characters consistent.

Such things might not bother me in regards to a comedy about zombies if so much else of "Zombieland" hadn't risen above normal conventions and cliches. The film almost seems to invite comparison to superior horror-comedies when two characters watch "Ghost Busters" during the second act of the film. While "Zombieland"'s makers might have wanted to pay homage to such a classic film, they inadvertantly reminds the audience of how horror and comedy can really cook if done right. Just watching Harold Ramis analogizing a Twinkee to a great paranormal disturbance made me wish I'd stayed home and plopped in that DVD instead. I didn't expect "Zombieland" to be a classic but I didn't expect it extend comparisons, either.

Forgiving those transgressions, "Zombieland" is clever and fun enough to earn your time and money. Plus, it gives you a reason to work out. "Cardio" is the best way to survive a zombie attack. Add that to the reasons.

Three stars (out of five)

"Zombieland" is Rated R for horror violence/gore and language.