Back in 2009, Zack Snyder adapted the popular, grim graphic novel Watchmen into a lengthy live action film that closely resembled the look and feel of the original story. Although adjustments were made to the story and the reception of the film was pretty divisive, Warner Brothers wanted to make Watchmen a household name like Batman or Superman.
One of the ways they went about doing this was to make a video game for these characters. While we did get a Watchmen game in 2009, we could've gotten something much more unique and cooler. After Zack Snyder's success with the film 300, Warner Bros. reached out to him to get him on board with the Watchmen film adaptation. Snyder accepted and Warner Bros. moved forward with their other plans for the Watchmen IP which included the video game that would be set in the universe of Synder's film.
The developer chosen to take on this project was BottleRocket Entertainment, a team comprised of some of the people who worked on the PlayStation 2 title The Mark of Kri. The studio had two ideas for a game. One being a cross between the Batman Arkham games and L.A. Noire (both of which hadn't been released at this point) and would star Rorschach as the playable character. It would've been an open world game which would see the brooding man investigating cases in an "investigation mode" and interrogating enemies with brutal animations. This game never got beyond just an idea, there were no gameplay prototypes made and the only thing really ever made was some concept art.
The other idea was a game that saw players exploring events prior to the film that are briefly touched on in the graphic novel. In the opening of the film, we see The Comedian murder John F. Kennedy on November 22nd, 1963 as opposed to Lee Harvey Oswald. It's quick and really only shows The Comedian walking away after Kennedy is dead but BottleRocket felt there was more there and wanted to dedicate a whole level to the assassination of Kennedy and escaping the chaos that unfolded afterward. There would've been other levels set during The Comedian's time in the Vietnam war, the riots prior to the outlawing of masked heroes, and more.
The game never came to fruition because Zack Snyder was unhappy with the contract that Warner Bros. worked out for BottleRocket and he told them to rework it. During this time, Bottle Rocket was running low on money and was scared that if they didn't find work, they would have to close down. The team was eventually offered the chance to work on a game for another superhero IP, The Flash but that's an entirely different story for another day. You can view the video about the project from Unseen64 above if you're interested in some more details and a look at some concept art for the games.