Superman: The New Superman Adventures aka "Superman 64" (partially found deleted content of Nintendo 64 action-adventure game; late 1990s)
Superman: The New Superman Adventures (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 being considered one of the worst video games of all time, due to its clunky graphics, irresponsive controls, very repetitive gameplay (many "fly through rings" portions), confusing layout and mediocre rendering, among others.
Superman was developed by the French studio Titus. In an interview with YouTuber Jon Carlton "ProtonJon" Wheeler (as part of Wheeler's ongoing let's-play of Superman), head developer and Titus co-founder Eric Caen revealed that the game was developed into something different, containing elements such as a wide-open sandbox world in the city of Metropolis.
However, the DC comics executives forced the developers to make many changes, including Superman not being allowed to hurt regular people, which led to the infamous and weird "computer simulation world" that serves as the game's universe.
The Superman animated series was airing its last episodes on TV, and this forced the developers to rush production of the game with little time left, which inevitably led into the product that came to be.
A 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 Eric Caen explained that he is not allowed to detail what was removed.
This potentially means that a Non-Disclosure Agreement is still in the game.