Using Cirque du Soleil dancers, Microsoft unveiled Kinect, a long-awaited motion-sensing accessory for the Xbox 360 video game console.

The introduction was made virtually without words, as is the custom with Cirque performances. Instead, Microsoft showed off Kinect, formerly called Project Natal, and its games through videos and staged live performances. The spectacle, which will air on MTV on Tuesday night, was a unique and very mass-market way to launch Kinect.

Ahead of the show, Microsoft handed out white satin ponchos with big shoulder pads to everyone without explanation. As I walked in, the place literally looked like a zoo, with animal-like Cirque dancers all over the place. Half the audience sat in chairs and half mingled with the Cirque dancers on the show floor.

Then the Cirque dancers began dancing and led a big elephant out on the floor of the Galen Center at the University of Southern California. The audience parted to let the elephant through and then closed ranks. I thought it was a well-trained elephant until I realized it was fake. There was a definite jungle theme, with cartoon jungle imagery splashed across huge screens that wrapped around the oval-shaped center’s balcony level.

Then drums began pounding and a singer began chanting. A couch with a family sitting on it rose from the floor into the air, roughly 75 feet above the audience. Then a kid made his way through the crowd, tossed a ball into the audience, and more dancing ensued. A young teenage boy atop the elephant climbed up some rocks and started playing game consoles, with the images showing up on a big screen. Each screen was lifted, revealing another behind it. He was moving from one generation of technology to the next. Finally, when he got to the last screen, the rock he was standing on turned into a glowing green Xbox 360 orb. The crowd of a couple of thousand people cheered as everyone’s satin ponchos all started glowing green. And then the word “Kinect” appeared on a screen. That had to be the most unique introduction of a tech product I’ve ever seen.

Next, the kid climbed into a big box in a wall that turned into a faux living room. He started playing Kinect games. The box turned upside down, with some of the people in the room walking on the ceiling and others walking on the floor. They started playing motion-sensing games and the images on screen showed up on the big screens that wrapped around the center. That was how Microsoft essentially “announced” each new game. I would show you what they looked like, but no videos or cameras were allowed.

One of the coolest new features was a video phone. You could tap on the image of a Facebook friend and then initiate a video phone call. While talking to the person, you can see their image on the TV set, using an Xbox Live connection. You can share pictures using hand gestures and talk using voice-over-Internet protocol.

USA Today accidentally leaked the news about Kinect early — or so I was told by a staffer. All of the games were responsive, but they weren’t necessarily happening live. We couldn’t tell if it was really just videos playing. I strongly suspect that the games were not live.

• Kinectimals lets you train and play with a bunch of animals, including virtual cats such as lions, cheetahs and tigers. You could tickle or pet your pet, much like you can in the Nintendo DS game Nintendogs. You could lie on the floor belly up and the little pet tiger would copy you.

• Joyride is a cartoon-style racing game that resembles Sony’s Mod Nation Racers. You can customize your car in that game and then driving it by moving your arms in faux steering wheel fashion. You can pull your hands in and then push back out to speed up. This game was announced last year for Xbox Live Arcade, but Microsoft never shipped it. Instead, it is retooling it for the Kinect launch this fall.

• Kinect Sports is like a knock-off of Wii Sports, only with different games and more active game play beyond using your hands. You can box, bowl, play beach volleyball and soccer, and race your friends in track and field. To do actions, you perform an action that mimics what you would do in real life, like kicking in the air to kick a ball.

• Kinect Adventures has a two-player race where you can ride a river raft through rapdis and make the raft turn or fly through the air using your body motions. This one looked like a lot of fun for those who like to exercise and laugh while playing with friends.

• Dance Central, in development by MTV Games, lets you learn a bunch of dance moves while you’re being instructed by a DJ. The camera in Kinect detects whether you are performing the dance well or not.

• Star Wars: The Force Unleashed II. This game wasn’t mentioned by name, but it was clear that this was what was displayed on the screen. You could swing your arms and fight enemies with a lightsaber. And if you pushed your hand in a direction, you could toss Imperial stormtroopers as if they were rag dolls.

• Tinkerbell. There was a scene where Tinkerbell was flying around as fireworks went off around Cinderella’s castle. I caught up with Graham Hopper, head of Disney Interactive Studios, and he said, “We haven’t said anything yet. Clearly something is going on.”

There was also an unnamed yoga/tai chi-inspired title where you had to do the same moves as your instructor. Microsoft communicated all of this without any formal descriptions. We’ll hear more about those at a press conference tomorrow. Sadly, I had to turn in my white satin poncho as I exited.

[Update: I attached a video below of Microsoft’s press event on Monday, with the same LucasArts demo of the Star Wars game for Kinect; this video is not from the Cirque show, but it gives you the same idea].