How is it that series become tired? Do the game designers become bored? Do they run out of ideas for plot and puzzle-filled gameplay? Do they feel that fans who flocked to the previous game will automatically plunk down $50 without getting something truly novel for their hard-earned simoleans?

The original Destroy All Humans! was a blast, figuratively and literally. Set in the 1950s when the UFO phenomenon was at its fear-filled, paranoid height, the game introduced Crypto, the so-ugly-it's-cute alien with the lightbulb-shaped head and mind-reading abilities. Crypto would feast on the brains of humans of that dumb-ass decade with alacrity. The things the dimwitted humans pondered, to which Crypto was always privy, were inane, funny and occasionally witty, just like the decade itself. As you flung cows around and anally probed the citizenry, you felt you were part of a parody that was, well, a lot better than what passed for humor in the often corny Leisure Suit Larry series. In Destroy All Humans!, you'd discover a huge world just by running around on the ground and exploring. You'd helm a flying saucer and blast the hell out of the humans that had become sheep, fat with the idea the America would never suffer again because the postwar boom would never end. Heck, there was even Ed Wood's "Plan 9 From Outer Space," the full movie, to watch at the drive-in if you wanted to take a break from gaming. Humor, satire, new gameplay and more than decent graphics: it was enough to make Destroy All Humans! one of the games of the year in my Village Voice column.

Destroy All Humans! 2 was more of the same, but because the peace/love politics and religion of the 1960s were rife for lampooning, there was enough to tickle the funny bone by exploring the proclivities of fat, psychedelics-loving hippies. New abilities like Free Love, which made characters dance wildly like birds on mushrooms, and weapons like the Burrow Beast, which sent an alien worm to devour nearby targets, not only had a certain charm, they were useful. The best part: Crypto's clone was the president of the United States. It wasn't only an inspired idea, but those among you who think beyond the game made parallels to the idiocy that is the current administration.

Which brings us to the semi-letdown that is Destroy All Humans! Big Willy Unleashed. The designers decided to place Crypto in the Disco Era when they probably should have placed him in the Punk/New Wave Era that was then overtaking the country with something really inventive, energetic and heretofore unfelt in rock music. Imagine Crypto going mano a mano with a phlegm-spewing Johnny Rotten character. Would that not be sweet? Plus, the Groovitron-like make-'em-dance weapon included in Big Willy was used in Ratchet & Clank Future and makes the game feel a little dated (even though Future and Big Willy likely started production at around the same time). Perhaps this letdown has to do with the fact that Pandemic, which made the first two games, didn't make the third. That task went to Locomotive Studios, which made a fine kids' game with Ratatouille and a middling but very playable kids game with Cars -- but maybe they should stick to charming games for the wee ones, not teen games for the Wii ones.

Here's exactly why. Big Willy, a 25-foot-tall mech that's also the mascot for Crypto's boss Pox's fast food chain, isn't that new of an idea. I mean, didn't we see a giant fast food mascot running after Homer in EA's The Simpsons game recently? He wasn't a mech, but the Bob's Big Boy mascot-imitation was indeed transmogrified. Yes, once Crypto climbs into the back of Big Willy to control him, he uses telephone poles as weapons and eats cars for breakfast -- cool in a Godzilla kind of way. But one big Big Willy feature is grosser than anything Mike Judge thought up in "Beavis and Butt-head." That's because Mike Judge knew his limits. A farting Shrek was kind of funny in a game, as is a farting Big Willy, but puking in a game (called the Regurge A Tron) makes me want to hurl, just like every time someone blew chunks in my elementary school. The Rule of Hurl: You see someone hurl and you are forced to do the same yourself. It's a chain reaction. Puking should not be the big featured weapon in a game. Tasteless, I can handle. Tasteless, I can like. But bodily-function grossness -- that makes me want to put down the game.

The plot itself is derivative: Pox's Big Willy eatery franchise has a mystery meat made of, oh, you can figure it out -- but they must have seen "Soylent Green" for inspiration. Colonel Kluckin' (it would be really funny if the Colonel had colon problems) wants to be the big franchise in the country and he'll stop at nothing to swiftboat Pox's chain of restaurants. See, corporate greed, even if it were written by Jon Stewart's writers, just isn't enough of a plot to sustain a humorous movie, let alone a game that can last 10 hours or more without the side-missions.

It'll take a while to truly master the Wii controls, probably about a half hour of play, all told. Yes, it's fairly easy to lift and throw cars and to pilot Big Willy, but the Wii remote is used to control the camera, and the camera tends to go wild and reckless. The latest weapons are just OK, but Crypto does have a choice of one pretty amazing idea that works well in implementation: Crypto's zombie gun, which turns all humans into the undead. Once these undead attack other humans, they become zombies, too. As for Big Willy, the coolest way to recharge this mech isn't by goosing him with a lightning ray. It's by having him pop a few humans down his maw as if they were Orville Reddenbacher's best. That's fun -- but not enough of Big Willy Unleashed is full of these Wow moments.

There's nothing special about the multiplayer aspect of this Wii offering: It's just you and an opponent shooting each other with rays and other weapons in two missions. Sadly, multiplayer must have been either a postscript or something the designers couldn't implement fully before deadline. Guys, do the Punk Era next time, and take the time to do it right. If you haven't played a Destroy All Humans! game, or if you have been yearning to play the new version, try it. For those expecting a lot because of the general likeability of the previous clever games in the series: fry it.

This review was based on a retail copy of the game provided by the publisher.