A Nightmare on Elm Street is a 1990 action-platformer released on the NES based on the horror film series of the same name. It was created by British-based developer Rare, known for the Donkey Kong and Banjo-Kazooie series, and published by LJN who are infamous for releasing licensed games reviled for their nonsensical gameplay and glitches. Gameplay focused around the teenage player character traveling to different locations on Elm Street on a mission to find and destroy Freddy Krueger's bones, the only method of permanently killing him, all while attempting to keep their sleep meter from depleting. When the bar is emptied, the character is transported to the Dream World where they can be openly attacked by Freddy and a multitude of super-powered enemies. To defend themselves, the character can collect tokens that can turn them into one of several special dream roles such as wizards and ninjas. Most if not all of the gameplay and story elements are directly lifted from the third movie in the series, The Dream Warriors.
The game went through notable changes over the course of its development with evidence to suggest that it was altered completely from the earlier build that was advertised in gaming magazines. According to an advertisement featured in a 1988 issue of Nintendo Power, the original intent was that Freddy himself would be the player character with the goal being to murder the teens attempting to find his bones. Players would be able to freely traverse the Dream World by warping through pipes, electrical outlets and mirrors, painting a fairly ambitious picture compared to the finished product. In Nintendo Power #2, a poster advertising upcoming LJN licensed titles was bundled with the magazine and Nightmare was among the featured games; the blurb once again mentioned that Freddy would be playable. There was radio silence on the game up until Fall 1989 when, in Nintendo Power #8, it was featured in an article about the NES Satellite peripheral. This time, the player character was advertised as being an Elm Street teen (one out of four if the Satellite was used). The article included two more screenshots from the prototype of what would become the title screen and one of Freddy fighting a group of kids, arguably still the player character by this point. Although LJN had apparently begun restructuring the game by 1989, the presence of these images, most of which include assets that would be used in the finished product such as the title screen, seem to imply that development had reached the point where the game's beta build was mostly playable. It was delayed until 1990 which further implies retooling on Rare and LJN's part.
No official explanation has been given for such a radical change, but considering Nintendo's reputation for producing family-friendly games and the financial failures contributed by earlier licensed horror games The Texas Chainsaw Massacre and Halloween (many game stores refused to stock the former due to the fact that the killer was playable), it's entirely possible that LJN ordered Rare to remake the game with a safer concept to avoid drawing controversy. Aside from the screenshots and articles listed, there is little to no information on the beta, its whereabouts or if it still even exists. Since LJN has been defunct since 2000, the only possible means of obtaining any information on it rests with Rare.