Ecco the Dolphin Defender of the Future 
Dreamcast
Sega Dreamcast
 
Plunge into the tropical waters of the Isle of Tranquility. As Ecco, an anergetic young dolphin you will explore mysterious locations that span four alternate timelines. Seek the majestic city of Atlantis, monument to the civilisation built by humans and dolphins. Encounter sea creatures and come face to face with alien forces as you seek to defend the Earth and history itself!