The reviews of the Wii Fit have been all over the place, so now that I've unlocked almost everything, I figure I'll throw in my two cents.
PRODUCT DESCRIPTION
Wii Fit uses a balance board to monitor weight and balance during a series of exercises and games. The exercises and games are in four categories: Yoga, Strength Training, Aerobics, and Balance Games. There is also a body test that measures BMI and balance to 1) determine a "Wii Fit Age" and 2) track you against a weight loss (or gain) goal.
YOGA
I did some yoga (mostly with DVDs) before the Wii Fit. Except for an abridged sun salutation, the Wii Fit only works on a single pose at a time rather than a flowing series. As a result it lacks the full benefits of a well-structured yoga routine. HOWEVER, because the balance board monitors your form for each pose based on center of balance and weight distribution, the game is a good coach, particularly for a self-made yogi like myself. For example, apparently I had been putting too much weight on my feet during downward facing dog. I am now mastering a more even weight distribution, and the pose does feel better. I try to remember how that feels when I do my "real" yoga.
There are 3 yoga poses that do not use the balance board. I don't see much point in that.
STRENGTH TRAINING
This is a section I rarely use because it's full of real exercises! There are planks and squats and lunges. Despite doing the same monitoring as the Wii Fit does for Yoga I don't see much sense in doing these with the Wii Fit.
AEROBICS
Although the Wii Fit burns more calories than watching TV or surfing the Internet, this game will not dramatically burn calories or improve your cardio health. Still, there is some stuff I enjoy here. My favorite in this section are the various hula hooping activities. They do wear me out a bit, and I've noticed more definition in my abs, likely because hula hooping constantly for 6 minutes really works those muscles. (6 minutes is an advanced level that opened up for me. You start at, I think, 90 seconds. I also now have 10 minutes available to me, but I'm afraid of it.)
Aerobics also has a couple of mild DDR variations. They're pretty boring (and the song is maddening), but I sometimes use them as a mild warm-up. There is boxing that is more challenging (at least the advanced levels are) for pattern matching, so I enjoy that a bit more.
The aerobics section also has some running options. Although I occasionally use the short distance option as a warm up, I don't find running around my living room to be interesting enough to do these often. Also, there is a version of the step routine that can be run when you are watching TV other than the Wii display. Commands and counts are given with the Wiimote. It's pretty boring and killed my calves. I guess, though, if it gets a couch potato up for a bit that's good.
BALANCE GAMES
The balance games are the most fun part of the Wii Fit. Using your balance you head soccer balls, ski, snowboard, navigate down a river, walk a tightrope and more. Theoretically they improve balance (which I need help with), but mostly I just like them (some more than others).
BODY TEST
An early review of the Wii Fit was unhappy that the game made you weigh yourself every day. Either they changed the game or that guy was doing it wrong, but you don't have to do the body test everyday (although if you go a long time without one, the game will encourage you to do it.)
The Wii Fit age is pretty much bullshit. It varies dramatically depending on which balance test is randomly chosen for you. (As the game tells me, "walking in place is not your strength." Thanks.) Still, it's interested to monitor my standing center of balance. It is a bit to the left. I actually knew that because it is the source of my back problems. I'm hoping that being able to visually see where my COB is I will be able to get myself straightened out.
One interesting thing about the body test is that it adjusts the girth of your Wii Fit me based on your BMI. One member of my household was displeased with that.
MY ASSESSMENT
I like the Wii Fit, particularly the balance games, yoga, and hula hooping. Is the Wii Fit a robust fitness program? No. Even the Wii Fit doesn't claim to be. One of it's daily tips told me I should try to exercise 30 minutes a day, but if I can't do that I should at least try to get 30 credits (minutes) on the Wii Fit. I took this as the game acknowledging that it cannot replace "real" exercise.
Still, I find the Wii Fit to be fun. If it keeps me off the couch for a bit, that's good. If I gain a little something from it that's great. However, if I'm in good shape for the summer it'll be because I'm improving my diet and doing other exercise, not because I finally navigated my bubble down that damn river!