Ecco: The Tides of Time
The followup to Ecco the Dolphin, in which Ecco successfully destroyed the Vortex. Unfortunately, it turns out that the Vortex Queen followed it to the Earth and eventually destroyed the Asterite. All the world's oceans are threatened, and actually already doomed.
In order to restore the Asterite and finally defeat the Vortex Queen, Ecco will have to confront once again the tides of time, which have split into two possible futures, the regular one and the dark one dominated by the Vortex Queen.
Ecco: The Tides of Time features even better graphics than its predecessor, and introduces a new gameplay mode in which the camera follows the dolphin from behind instead of from the side.