The alpha version as it appeared in an Ebay video.
Sentinels of the Universe was to be the sequel to Ecco the Dolphin: Defender of the Future. It was in development for the Sega Dreamcast but was cancelled in the early 2000s when Sega discontinued the console and largely ended first party support. The project was cancelled instead of shifting development to PS2, Gamecube, or Xbox. Other than the mysterious title, not much is known about the game other than what was seen in an Ebay video supposedly showing the game running on a Dreamcast development kit.
