For each era, Bugs is sent through time but also to other locations of the world. From an area over water, Bugs moves to America in the Thirties level, then back to Europe for the Medieval era (because, there are no castles in America, duh), and then... space. Clearly the time machine drives Bugs to the most important place on Earth for the time period he visits. So, if he's in space for the last world, Dimension X... Doesn't that imply that there was nowhere on Earth where he could go? Even worse, Dimension X is Marvin the Martian's lair. This could mean that Earth might have been vaporized by Marvin. Gulp...
Either Marvin actually succeeded in shattering Earth with the KaBoom he always wanted to do or Bugs was sent to a point in time in the future when Marvin didn't do it still due to being busy with other things and Bugs was just there to pester him.
