These replacement Joy-Con controllers work just like the original controllers. They fit the sides of the Switch, a third-party charger I have, and the original Joy-Con grip. I tested it with Mario Kart and everything worked fine. The controllers connect via Bluetooth just like the originals, with no need to select buttons other than the home button, which activates the Switch. Interestingly, each controller can be charged via the USB-C port on the side. I can't say anything better than that I can play games with it just like I did with the original Joy Cons that came with the Switch.