eBay watchers have noticed an auction for a prototype of the unreleased Echo Delta, a game once in the works between Nintendo partner Marigul and CleverTrick. Marigul was also responsible for Hey, You! Pikachu, Custom Robo, and Doshin the Giant.
The seller describes the game as follows:
...from what I played so much, it is addicting and has really great sound, awesome animation and control. Of the submarines that you play you can pound into the other guys its one of the many fun parts of the gameplay. Starcraft 64 and maybe Ogre Battle can sort of be compared since thats all we got but... The underwater element is really unique and unexpectedly surprising, giving way to its own whole world and genre.
It's been rumored that this was the version previewed by IGN64 back in September 2000, but it's also worth noting the screenshot on the auction shows a 2001 date. In any event, the game was never released neither in America nor in Japan, and is not likely at this point to ever do so.