You have to ask why any developer would waste hundreds of thousands of dollars and the time of a crack development team to bring out a moving work of immersive storytelling like the tragically underappreciated Eternal Sonata (which I'm currently playing), when consumers are going to have exactly as much fun interacting with some two-dimensional drivel about an Incan frog that shoots balls from its mouth.
It's PopCap Games that are at fault. As a developer, they've set their sights firmly on making oodles of money by selling these repulsive "casual games" to women, the elderly, and other minorities who don't know any better. There are billions of these gaming parasites sitting in front of their computers right now choosing to purchase PopCap's low-production-value dross and by extension depriving wonderful creators like Quantic Dream or Double Fine of the piles of currency that should be rightfully theirs.
I'm playing Zuma right now. I can't stop. It's the aforementioned game about the ball-spewing frog, and tearing myself away from it is becoming a physical impossibility. It's like the McDonalds of gaming, and like McDonalds it tastes foul, is bad for me and diminishes my interest in experiencing anything of genuine quality.
Basically, you're a frog, see, and you sit in the middle of a looping path, along which flow a progression of coloured balls. You can insert balls into the path by shooting them from your mouth, and when you create groups of three or more balls of the same colour they vanish and score you points. The vanishing can then let more balls link up, making more sets of three, et cetera. All the while the balls march relentlessly towards the end of the track, and if they reach it, you lose. You can roll the whole line back by getting combos, and once you hit a certain number of points on a stage new balls stop joining the line, giving you the ability to finish the stage.
Zuma's got just that mix of responsive controls, rewarding sound effects and shiny colours that makes games like this click, and before you know it the thing will be squatting in the pleasure centres of your brain and playing you like a fleshy marionette. You can get it from XBox Live Arcade, but getting rid of it will probably require a priest and some holy water.