I lost over 100 pounds using this software!
It's an interactive workout video, that tailors itself to your level of fitness. You're not even going to be holding the controller, except to quickly rate how difficult a section of your workout was, about once every ten minutes. It will gradually ramp up the difficulty over time even if you say it's 'just right', so occasionally it'll throw something at you that you can't quite do, but all you have to do is tell it you couldn't keep up, don't worry about it, and it'll adjust for you.
The software is well done and the music you'll work out to is pleasant, at least if you like video game music. You will notice a couple of technical glitches here and there, though, but they're nothing that breaks the software or ruins the experience. Sometimes it looks like you're going to be taking a breather, but instead you keep doing the same exercise for another round; after it does this to you a couple of times, you'll be able to predict when it's going to happen, so it's no big deal. And there are some amusing clipping issues with the optional hand weights during a couple of exercises, but just don't hit yourself in the breasts with your own weights the same way, and you'll be fine.
I've been using this as one half of my fitness program for over a year now, and I've really seen great results. I admit that I don't use the included meal planner; it's really basic and there are much better nutritional planners available online for free. (I like the wellness tools on LeanCuisine.com personally, but it's up to you.)
So it really is that easy: Find your metabolic rate and count your calories with an online tool, and commit to a 30-minute workout with this software 3-5 times a week, and you can be slim and trim too! It worked for me.