My favorite wall-of-text site has plenty of information on this
merchandise-driven duelfest, but Blue pretty much nailed it.
Nice shots here. This certainly is a step above... what was it? Oh yes, Battle B-Daman. That's kids playing with marbles.* There are dragons and other "giant" beasts, but they only ever manifest as translucent shadow-things with no clearly defined lower half. Or was that Beyblade? That's just kids spinning tops! What's next? Miniature monsters hiding in jacks?
*"Apparently, in the "B-Da World", a person's social position, level of respect and moral actions are defined by playing marbles. Not playing B-Daman is something so bad that people don't even recognize you as a person (that's the message that the first episode gives to us). And of course, playing with marbles is also a good way to take over the world and be a world-threatening criminal."