Source: Various screen shots from Ecco: The Tides of Time - http://www.megalextoria.com/wordpress/index.php/2017/06/05/ecco-the-tides-of-time/
Ecco: The Tides of Time was the sequel to Ecco the Dolphin and was released for the Sega Genesis and Sega CD in 1994. The CD and cartridge versions are not hugely different but the CD version adds a new soundtrack and a few other small touches that make it worthwhile if you have the Sega CD. There was also a Game Gear version but it was significantly different with a number of levels removed completely. There was a Brazil only release for the Sega Master System that was somewhat better than the Game Gear version.
The Ecco series is quite unique and it seems as if people either love it or hate it. It is a somewhat surreal game with the player controlling a dolphin that ultimately ends up saving the world from aliens. It can be a difficult and lengthy game but worth it for those that have the patience. The game was re-released on Wii's Virtual Console in 2007.