Tidal Tempest boss

Bubble Shield Blaster is the third boss encountered in Sonic CD in Tidal Tempest, piloted by Dr. Robotnik.

Close to the end of the third act, Sonic will find Robotnik sitting in his hovering Eggmobile, which will begin to fly into the depths of Tidal Tempest. The player can hit Robotnik four times, before he departs into the sea. Once the player does the same, he/she will find the doctor floating in the water, which will begin to form a shield of bubbles around it. Robotnik will partially dive towards the player while his bubble shield spins, and will fire a few projectiles at the ground. Sonic, however, has an advantage here, as the bubbles are the main oxygen supply to survive underwater, and once a bubble is gulped it will leave one less around the Eggmobile. Once most or all of the bubbles are gulped, the player only needs to hit Robotnik once more to defeat him, and then the water level will drop through the floor.