Like the most of you know, the Death Egg was destroyed in Sonic's third big adventure and Robotnik hasn't enough of resources to build a new one or even a new Badnik army. So he takes what he haves and builds the Brick Egg it's a smaller version of the Death Egg and it makes little stone bricks out of rocks that it bombs the ground with. Now Sonic and Tails have to stop this machine before it's too late.