Do you hate jellyfishes? No? What about monster jellyfishes? What about over sized, monster jellyfishes that hate nuclear reactors to the point of headbutting them to death, destroying, in the process, the only energy source of the small, isolated floating fortress where you and your dear family spend your living days?
What about now, do you hate jellyfishes now? Because in this underwater shoot'em up you (that's right!) get to pilot the submarine unit Defender 88 (D-88, for friends and acquaintances) and to protect three generators with your life, machine guns and mighty torpedoes. Dash like a madman through curtains of bubbles, dodging ever increasing waves of evil medusoid creatures while shooting them in the face. Do jellyfishes even have faces? They do now.