Superman: The New Superman Adventures aka "Superman 64" (partially found deleted content of Nintendo 64 action-adventure game; late 1990s)
Boxart of the game.
Status: Lost
Superman (although widely referred as Superman 64) is a Nintendo 64 video game released in 1999, based on Superman: The Animated Series. It is infamous for its perceived extreme lack of quality, clunky graphics, irresponsive controls, very repetitive gameplay (many "fly through rings" portions), confusing layout and mediocre rendering, among others.
It was developed by the French studio Titus. The head developer later revealed in an interview that the game was developed into something different, but the DC comics executives forced the developers to make many changes, which, combined with the short time left to work on, inevitably led into the product that came to be.
One beta rom was revealed, but it is unknown if there is more developed content yet unseen. However, it is extremely unlikely that any of this will be revealed because in an interview of Eric Caen (co-founder of Titus) by YouTube user Proton Jon, he explains that he is not allowed to detail what was removed. This potentially means that a Non-Disclosure Agreement is still on the game.