Ecco the Dolphin, released for the Sega CD in 1993, stands out with its innovative gameplay and marine exploration theme. Players control Ecco, a bottlenose dolphin, who traverses the ocean's depths and mysterious underwater caverns to rescue his pod from a mysterious threat. This action-adventure game combines puzzles, sonar-based mechanics, and an environmental narrative, set within a captivating underwater world. It is well-celebrated for its challenging gameplay, atmospheric soundtrack, and early use of echolocation as a gameplay mechanic within its genre.