I first played this gem on a sampler CD that included Three Dirty Dwarves, Clockwork Knight 2, and Virtual On. While we know the respective fates and doomed obscurities of that lot, Baku Baku never received the recognition I thought it deserved. This is an addictive puzzle game that plays even better against another human friend. Chain reactions occur on a very random basis, though, and sometimes a round will end without either person realizing they were so close to victory. Such is the plight of games about animals that eat food.
There is some convoluted back-story about some kid that battles various passersby in a round of Baku Baku, slowly working their way up to the King, or Grand Master, or some such paradigm. The story in a puzzle game is about as important as the story in a shooter. It's all about the gameplay, which Baku Baku has in spades. Basically, a block with two squares will fall, and the block will either contain animal squares, animal food squares, or a delicious combination of both. The object is to match the animal square to the food it eats, and to rack up those sweet sweet chain reactions. There are, as evidenced by the instruction manual, five animals and five foodstuffs, but most people won't play long enough to see the Mouse and Cheese squares, and they aren't present in the multiplayer mode.
Baku Baku contains a wonderfully "Japanese Game" soundtrack; meaning it employs that kiddy techno style music the region's more obscure games are known for. The sound effects are very reminiscent of Pac Man, particularly the eating sounds. Graphically speaking, the Master System counterpart is gracefully put to shame with more polished 3D effects and an all together cleaner appearance.
I would recommend picking this game up if you can find it reasonably priced. Our local used game chain likes to price their games "eBay-style", which makes it hard to get a good deal. Lest your stores do the same, this one shouldn't set you back more than ten dollars.