40 Winks (found Nintendo 64 port; 1999)
40 Winks was a platformer game developed by EuroCom for the PlayStation. However, a Nintendo 64 version was planned and edged very close to being finished, even receiving a review from the Official Nintendo Magazine. In late 1999, the publishers began debating whether or not they should release the game for the Nintendo 64, with IGN calling its future "uncertain." Ultimately, they decided against it, and the port went unreleased.
The English, Spanish and Italian prototypes were released on a popular ROM-hosting website, and it can be discovered through a simple Google search. It is currently unknown why the game was cancelled.