Quartz Quadrant boss

Mine-Dropping Conveyer Belt is the fourth boss encountered in Sonic CD in Quartz Quadrant, piloted by Dr. Robotnik.

Once Sonic runs into the arena, he'll find an indestructible booth separating him and Robotnik. A conveyer belt will activate while spikes lower from the left side of the screen to block the entrance. The only solution is to run along the conveyer belt while the doctor moves a crane and drops small mines, which detonate into four small mines that don't travel very far at all. The machine, however, is a self-destructing mechanism, and the booth that contains Robotnik will lower against the conveyer belt after a period of time, beginning to destruct. Eventually, the machine will explode and the player is granted access to the end of the level.