Looks like Marvelous’ mysterious counter is for a PSP game as well. The upcoming issue of Weekly Famitsu has a 2-page report on Yuusha 30 (Brave 30?), a “new feels RPG” about saving the world in four different game modes. One of the character can be seen carrying the same clock featured in the countdown page.
The game modes will all play differently from each other and each of them has its own main character too, they are brave fighter in side-scrolling action, princess in shooting game, devil king in strategy game and knight in action game. Interestingly, you have only 30 seconds to clear each of these modes. Still not sure how exactly this will works but it certainly sounds intriguing, more information as they become available.