Sewer Shark

When I got my SegaCD, this was the game that came with it. The gameplay gets tiring as all you do is shoot things as you fly through a sewer. You also have to make sure you go the right directions or else you'll crash and explode. Your mission is to keep the sewers clean and free of "rat-igators", huge scorpions and other assorted bogies. Ghost is your co-pilot, who taunts you into action and gives you a variety of callsigns. Catfish is a flying robot pal who scans the area ahead and helps navigate you through the underground. Eventually you'll get contacted by Commissioner Stenchler, who kinda looks like Danny DeVito. He's the boss up on the beach with his bimbo secretary and bets you can't make it to Solar City. I wouldn't have gone out of my way to get this game but it is a Sega CD Classic.