Let's Tap, revealed as the first mystery project from Yuji Naka's new company Prope, have come up at the game's official site. When we saw the video last night (and even before that, when Prope teased a game that "even penguins could play") we assumed it was a Balance Board-type thing, but it would appear based on the background of the site that the tapping is done on the B button of an upturned Wiimote.
The site reveals some other interesting tidbits about the game too. Coming out in Japan in December, Let's Tap is listed as a "Tap Action" game that can be played by "1-4 players (up to infinity)." We love the weirdness of the concept, and we love the varying, sometimes abstract, visual styles found in the screens. We'll find out more in a week, when the site opens for reals.