I'll let you play the game, I'm more interested on how they used this free game to promote their not-free screensaver : apart the classic "more stuff" on the menu screen, a flashy "Get cool screensavers here" button is available on the game screen.
I'm good at Sudoku no ? :)
I would be very interested to know how many people actually click on this button.
It's a good idea to use a (now) classic game like sudoku, there is always a lot of people looking for mobile version. And I think the 2200 downloads on GetJar the first day is a perfect example.
I also notice they used a mobile payment solution I didn't know yet : Bango