As garbage flows in and you're starting to make a decent-sized pile, you'll notice that placing certain objects on other objects of a different type will cause them to break -- ultimately altering the sizable footprint of any object. For example, if a giant Buddhist bell that's made out of metal is in the trash pile, anything that hits it and is made of wood will shatter into pieces. If the item happens to be a wooden coffin, it becomes nothing more than a pile of boards.
Material composition is just one thing. It gets slightly more complicated as the elements are added. After playing a bit further, you'll notice that you might get something that looks like a sword on fire. This means you can start burning trash in your bin. Anything that actually could catch on fire or combust in real life will do just that at the touch of this item. The idea here is to chain combustible trash. After awhile, the trash will explode and be removed from the bin. Another way of getting rid of trash is to smash open objects that contain water and start flooding the bin. Doing so will slowly rot away the items in the water. You'll want to do this so you can continue filling up the bin without overflowing.
Interestingly the game also has "bosses" -- or at least, boss items which need to be thrown away in the bin. They are significantly more difficult to work with. The one we saw was a rather large truck, which due to its size, was a tougher to find a spot for. All things considered, including the material composition and elemental effects, there's actually quite a lot going on here. The more difficult levels will certainly be interesting to see. When a stage is cleared, you'll be given a rating of either ECO (good) or EGO (bad) depending on how much trash you've disposed of.
Underneath Gomibako's Tetris-like gameplay lies a social consciousness teaching us the importance of good waste disposal. Japan is no stranger to efficient plans on keeping its environment clean and green, and we'd like to think the game's concept would reach out positively toward that crowd. In fact, it was the most popular PSN title among the Japanese gamers who waited in line to play PSN games. This strong localized taste has us worried, though -- worried over whether the title would be released elsewhere. If it isn't, we'd most certainly be disappointed to miss out on such an interesting game.