What if you could turn exercise into a fun game? That's the idea behind "Wii Fit." Anyone who has experienced the Wii's motion-controlled games knows that playing them can be quite a workout, but "Wii Fit" takes that concept to a whole new level of exhaustion.

The main component of the $90 package is a hefty balancing board -- similar to the platform used for step aerobics. The wireless accessory basically is a sophisticated, floor-based game controller. It senses your weight and movement as you step on it and uses that data to control onscreen games and exercises designed to improve your balance, posture and fitness.

I set it up and give it a go. The first thing I see on the screen is an animated version of the balancing board along with overly cute music and voices. It wants to know my height and birth date. I'm prompted to step on the board to measure my center of balance.

I lean to the left. I lean to the right. I'm trying to get two opposing bars to remain stationary in a designated area on the screen by shifting my weight just so, but by the time I figure out how to do it, my 30-second limit has expired. I don't finish the fifth and final round.

"Looks like the Basic Balance Test isn't your forte," the screen says. "Do you find yourself tripping when you walk?"

The board then weighs me. It calculates my Body Mass Index (BMI) at 27.33. Anything over 25 is overweight. Dang. I could stand to lose about 13 pounds.

"Wii Fit" can help me lose those pounds through four types of exercise: yoga, strength training, aerobics and balance games. It will keep track of what I do and how much time I spend on them. I can enter a target date on a calendar and it will help make sure I stay on track to meet my goal. I earn points based on my performances. As I do better and log enough minutes, more activities and tougher challenges become available. This gamelike approach helps take my mind off the monotony of exercising.

I try the balance games first. The most fun is Ski Jump. I bend my knees and lean forward slightly, trying to keep my balance steady as my Mii (the Wii's onscreen version of me) skis down a ramp. Just before the end of it, I quickly stand straight and hold still as my Mii launches off the ramp and glides through the air.

Under aerobics, I try the basic step routine, which works much like "Dance Dance Revolution." Following an onscreen class, I step on and off the balancing board in time to the music. I do OK, I think.

In the yoga section, a realistic-looking human instructor demonstrates how the routines are done and New Age music plays. I opt for the Tree Pose, in which I stand on one leg for 30 to 40 seconds, with my free foot placed on my locked knee, and slowly raise my clasped hands above my head.

No problem. But I'm rated as just a Yoga Novice. It's that darn balance problem again. The board knows my weight continually shifted as I struggled to hold the pose. I can even see a graphic representation of it on the screen.

I fare little better under strength training, which also gets a serious presentation. While doing leg extensions, I have to put my foot down to keep from falling over. "Wii Fit" knows I did that, which affects my score: Couch Potato.

OK, so I'm unbalanced. I don't know if I needed "Wii Fit" to tell me that, but it might help me to correct the problem. In the process, I might just become more physically fit and lose some weight if I stick with it. And the game will keep track of everything for me and up to seven other people.

Sure, there are other ways to keep fit, but "Wii Fit" makes it fun and easy -- even for those who are unbalanced.