“Wii Fit”
Genre: Exergaming
Developer: Nintendo
Publisher: Nintendo
Platform: Wii
Price: $90
ESRB rating: E (everyone)
Grade: A

Hard to believe, but right now, the most desired video game in the flabbiest nation on Earth is devoted to physical fitness.

Yes, “Wii Fit,” the eagerly awaited light-exercise game by Nintendo that debuts in the United States on Monday (May 19), has sold out online and can’t be found anywhere in the brick-and-mortar world. Web retailers such as Amazon.com expect delays of weeks or months before orders are filled, and clerks at stores such as Game Stop only shrug when asked when their next shipment arrives.

If it arrives, some say.

Overseas, where “Wii Fit” began selling months ago, overwhelming demand persists — enough that anyone who tried to sneak over from the States to buy it early more likely than not came home empty-handed.

So, given all this, Game Guy felt fortunate when “Wii Fit” arrived at his doorstep last week. He has few friends, you see, and in-demand titles such as this are about the only tools he has to construct a social life.

And suddenly, this week, he has lots of new friends.

The $90 game, if you can call “Wii Fit” a game in the traditional sense, comes in two parts: the game disc, and a white-and-gray-plastic balance board that is about the size and thickness of two bathroom weight scales side by side. The board synchronizes wirelessly with the Wii much like the wand-shaped controller and is about as easy to set up. Game Guy figures he spent more time taking the board out of its shipping box than he did getting “Wii Fit” and the board both set up and working.

Upon initial startup, “Wii Fit” asks players to designate a Mii avatar — one of the player alter egos for Wii gaming used in other Wii titles such as “Wii Play” and “Wii Sports” — then sets to work determining the user’s weight, body mass index and center of balance. This last factor is the most important, as it commands 90 percent of the interactivity in “Wii Fit.”

Once finished, “Wii Fit” then assigns a “Wii Fitness Age” based on an algorithm of the three factors and asks players to set goals toward changing it. Not a few players may find their fitness age to be higher than their real age — a byproduct of today’s sedentary, fast-food society. And “Wii Fit” spares nobody’s feelings: terse on-screen statements such as “Balance tests obviously aren’t your thing,” and “Oh, come on, you can do it,” are intended to tap into the shame Americans as a whole share for not staying in shape.

Players are encouraged to revisit the Wii Fit Plaza where these personal details are stored and take periodic tests to check individual progress on BMI and balance goals. A calendar with a little stamping tool also resides in the Plaza, so players can mark how many days they have played and see how much closer — or further — they are to their goals.

After setting those goals, the real fun begins. “Wii Fit” starts out by offering about 40 different fitness and skill routines in four categories: aerobics, strength training, yoga and “balance games.” Strength training and yoga are led by a “personal trainer” — you can pick whether it should be a man or woman — a gray-hued avatar that first instructs how to do certain routines and then voices encouragement to players who struggle to get through them.

Or, they express disappointment in anyone who, from the perspective of “Wii Fit,” lacks the requisite motivation or gumption. To be certain, anyone with a mild constitution or delicate ego may find the game’s admonishments rather biting.

(Game Guy’s favorite of these is the slight, high-pitched “Ohhhh,” the game makes every time he steps on the balance board. For the record, Game Guy never has been heavy, but you’d think he was Andre the Giant the way “Wii Fit” squeaks and grunts whenever weight factors into his performance.)

On the “fun” side are the aerobics and balance games, which employ all kinds of nuanced stunts mixing entertainment with exercise, such as step aerobics, hula hooping, tightrope walking, slalom skiing and ski jumping, and snowboarding. In one balance game, the player must lean gently left or right to direct his Mii as it floats in a soap bubble though a rocky canyon, taking care not to let the bubble touch the canyon walls. In another, the player sits as still and as centered as possible on the balance board to keep an on-screen candle flame from flickering; if the flame flickers too much or winks out, the player is slapped by an unseen yoga master.

Those last two are “unlockable” games — additional games programmed into “Wii Fit” and made available as players extend their exercise time or improve their balance skills. Other unlockables appear in the strength training and yoga categories, but these can be unlocked through aerobic and balance games, too.

Authentic yoga instructors and fitness professionals might find fault with “Wii Fit” paying too much attention to balance and not emphasizing enough technique. Mrs. Game Guy, a big fan of yoga, noticed a few errors with foot placement within some routines, but gave the game a passing grade anyway. And Game Guy, formerly a competitive runner, took issue with the instruction to swing one’s arms higher than necessary while running in place — which, by the way, is done off the balance board while holding the wand controller in one hand or stashing it in a pants pocket.

Good intentions aside, “Wii Fit” is still primarily a tool for entertainment, not a substitute for either genuine exercise or instruction from trained fitness professionals. Think of “Wii Fit” as a fitness program with training wheels for people reluctant to leap straight into a full-throated exercise regimen.

Game Guy spent the better part of three days working with “Wii Fit,” running through all the routines and unlocking the unlockables, and feels unlike he has with any other game — that is, he feels invigorated. He lost nine pounds and dropped his BMI by two and a half points, which was enough progress in a short time to make “Wii Fit” actually ask if Game Guy might be overdoing it. Though acerbic at times, “Wii Fit” also expresses concern for the well-being of its players, especially if the game thinks players haven’t taken 10 minute rest breaks every half hour. So, yes, if a player works hard enough, “Wii Fit” actually has something nice to say.

And so Game Guy is compelled to return the favor.