Hint #11: Duke Nukem (a side scrolling platformer/shooter) led to Duke Nukem 3D (a first-person shooter), Duke Nukem: Manhattan Project (a 2.5D side scrolling shooter), Duke Nukem: Time to Kill (a third-person platformer/shooter), Duke Nukem: Zero Hour (a third-person shooter), and Duke Nukem Forever (an archaeological dig through first-person gameplay tropes that surfaced during its development).
The theme has been guessed (genre change) and a post with all the details about the rules for the theme will be made on Monday.