No, the reason you're not seeing results anywhere close to that from anyone else is because this guy is full of shit. 

People fall for all sorts of stupid quick fix fads because they think diet/fitness is some mythical thing that impacts some people completely different.  

If you want to lose weight and you create a calorie deficit, you will lose weight. But it takes time, and 200 calories lost from 25 minutes of mild cardio is a drop in the bucket. There is no diet that can lose a giant ass gut like what that guy had without full on fasting in that time period. This guy didn't discover some magical thing that even top level bodybuilders, Olympians, Hollywood actors, and pro athletes don't know about. 

The only way to lose a gut like that in a month would be to fast and/or vomit up all the food you are eating (yes even "healthy food", calories are still calories they don't magically evaporate), light cardio is not going is going to be nothing compared to that. And even then it would be extremely difficult to do that. He's clearly using a photo from a year or more prior. 

My brother is seriously considering picking this one up as he's become overweight over the past year. And he's definitely not the kind of person who typically buys the Wii Fit/Just Dance "expanded audience" software.

Eh I know a thing or two about metabolism as I had an extreme metabolism in high school and had to power down mass gainer shakes with lunch and breakfast every day. Metabolism doesn't magically change calories in/out that much. 

That guy is developing man boobs in the photo he shared it's not just a gut with a body fat percentage probably in excess of 25% in his original photo.

If you could pull that off in 30 days every actor in Hollywood would pay him millions of dollars to come set up the same diet for them, with a laughable 25 minutes/day of light cardio only, lol. 

And for all your years lifting weights up and playing games in high school, your knowledge of basic nutrition and metabolism is about 8 decades out of date. Everyone did sports in High School and University, most people lift weights. You would have been much better off taking some nutritional sciences or biology classes instead of just gym.

You don't need to have a PhD in physical fitness to know that 25 minutes a day of light cardio for a month and some "diet changes" is going to get you that result in 30 days. I've worked in a gym for several years I know several personal fitness trainers.

There's no metabolism on planet earth that does that and thank god it doesn't because the human species would've died out for the majority of its existence where food was not readily available in a refrigerator or supermarket and you actually had to go for days without eating at times and still be able to hunt/chase your next meal in that process. 

To lose weight you need to create a calorie deficit, if you eat continually in excess of the calories you are burning off you are going to gain weight. As a person who has a high metabolism, that applies to me too, people think we're some kind of magical unicorn that can eat whatever, and that's also bullshit. There's no metabolism that changes that to any huge degree. 

What I got from my calorie counter was way more than just 200 calories, I got over 600 kilocalories per 30 minutes session, once even over 1000. I don't know where you get those 200 calories from

You also don't need a PhD to take a health class, you could have taken one in High School.

I don't know or care about this 25-minute guy. I am talking about your calorie-burning math.

It more or less does work. You're either in a state of calorie deficit or surplus or by fluke right down at equilibrium. 

There's isn't some alternate option there. If you are in a deficit consistently long enough you will lose weight. If you are at a surplus consistently long enough you will gain weight. 

I remember reading a study even that a doctor did about 10 years ago where he ate nothing but food from a 7-11 all day for like 6 months or something, but he controlled the calorie intake to be under what he needed to maintain his weight. Guess what? Even eating shit like potato chips and chocolate bars all day and Twinkies, he lost a large amount of weight, improved his cholesterol, etc. etc. 

People always want some fancy fucking answer for this stuff like some magical new diet craze or fitness product will magically do the trick, but it's really just calorie deficit. It doesn't even matter if it McDonalds you're eating all day, as long as you put your body into calorie deficit. The truth is most people don't want to do that because it's uncomfortable. They don't want to hear that, they want to hear about some trendy Miami Beach diet (which they ditch after 2 weeks) or some Ab Doer product they think will give them rock hard abs (uh no number of crunches is going to do a damn thing until you get your body fat down to a very low number). Saw that at the gym allllll the time, doesn't surprise me so many people are overweight, if you don't understand calories in/out and you're baffled as to why you're fat ... 99.9999999% of time it's because you're taking in more calories than you think. 

While I'll say, I don't buy that Ring Fit could magically make a guy ripped or lose a gut in a month or two, I do have to say that I think it's important to consider that a good chunk of this game isn't just cardio, but actual resistance training. This means you're constantly (or usually) working your muscles, and the time it takes for the muscle tissue to rebuild will take a day or longer which burns more calories over time - vs straight up cardio which burns calories more or less all at once.

The in-game calorie burning counter is neat, but I question how accurate that is. I was legit sweating bullets and completely sore doing squats for an hour with this game, and basically ready to collapse, and yet the calorie counter stood at like 270. I'm thinking there is absolutely no way I burned that few calories when I used to ride an exercise fan bike, and while I'd be sweating quite a bit I burned over TWICE the amount of calories after riding for an hour according to the bike monitor, and sure I felt winded but I was actually MORE exhausted playing an hour of Ring Fit with all the resistance training. I feel like the game is failing to count the calories burned from the rebuilding muscle tissue, which IS significant. Could be wrong but just my take.

Yes and no. Muscle exhaustion doesn't necessarily correlate to calorie loss, like for example it's very easy even within 5 minutes to exhaust your muscles to the point of near "collapse" (or lets say more accurately exhaustion) in any weight room by doing 80-90% of your max bench press or at the squat rack, but doing that 6-7 reps for 4-5 sets with minimal break in between, you're going to quickly hit a point where you've reached complete muscle fatigue. 

But that doesn't really mean the pizza you ate earlier in the day is now gone even though you feel dead and couldn't do another rep. 

If it worked like that, really standard cardio would be useless, you could just do 15-20 minutes of heavy lifting and push yourself to exhaustion pretty easily by super-setting, I wish that it worked like that because I hate treadmills and bikes, though I just run a basic basketball workout these days. I'll lift typically for 45-50 minutes, then 20-35 minutes of a constant motion basketball shooting drill, which for me is a lot more fun than a treadmill.