These Bluetooth controllers can be used in multiple ways. You can use them independently in each hand, attach them to a Joy-Con grip for a single controller-style unit, or snap them onto the Switch for handheld gaming. Each of these has a full set of buttons, so using one as a standalone mini-controller won't feel limiting at all. In fact, it's going to come in handy for some two-player sessions in games!
The Kinect was first revealed as Project Natal at E3 2009. Of the demos shown off, the most memorable is Project Milo, a simulation game by Peter Molyneux's Lionhead Studios. Project Milo's demo featured a player interacting with a child on screen, who was guided by the game's artificial intelligence to react to the player's words and movements realistically.