I recently bought a Quest for fitness as well, and while I was a bit unsure, I'm fairly convinced. (For reference, I lift weights about 4 times a week. I play basketball once a week or so, but don't do much other cardio, which is the hole that I was looking to fill.)
It's worth asking what your goal is though. If it's only to burn calories, what matters is a mix of intensity and how long you do the activity. Walking for two hours burns more calories than running for 10 minutes. So through that lens, a game that has you moving only a bit, but that you will play for an hour, is a pretty good idea.
If you don't have that much time, or your goal is more health-focused in that you want to get your heart rate up, there are definitely games that make that happen. A boxing game is considered the gold standard, but there are other games that definitely make me sweat.
All in all, it's an activity I enjoy doing, and that I can do every day without leaving the house, which for my specific situation is exactly what I needed.