I imagine it would have tired to have been more like the animated series but also possibly more like the Burton-Schumacher Batman films, with probably a bigger cast and more focus on action, effects and possibly humor rather than realism and characterization and probably would have been less successful.
Bryan Singer wanted more characters but was denied. I assume Ratner would hit a similar wall but judging from his over the top attitude, I bet he would have focused the story more on Professor X and Magneto with a bigger end battle as apposed to a Wolverine/Rogue centered story.
Watch the first few eps of the 90s animated X-Men series. Imagine Chris Tucker as a male version of Jubilee, sporting roughly the same wardrobe, fulfilling the same POV character role as Rogue. And there ya go.