ReBoot: The Guardian's Code is basically nothing more than a horrid superhero show mish-mashing elements of Code Lyoko and Power Rangers while using the ReBoot name and villains to make it more recognizable. Let's just say people hate it, as at the time of its release, the official trailer became one of the most disliked videos on YouTube, and even getting the creator of Code Lyoko to comment on their Facebook. So, with this episode, the final episode of season one, the team decided to make a episode with all the characters we love, and basically use it to bash the fans of the original show.
So basically, the plot is the Guardians find a supercomputer hidden, and activate it, finding Mainframe, the setting of the original. There, Vector and Enigma go in after Megabyte, and meet Bob and the gang. But it does not last long as Vector and Googz joins Bob in defending a part of it from the User, who is revealed to be a manchild who is a fan of the original show living in his parents' basement and waiting twenty years for the place to go back online.
Yeah, it's easy to tell this episode, despite revisiting the location and heroes of the original show, is nothing more than something made to insult fans of the original ReBoot. The user (played by Mark Leiren-Young, the person who actually wrote this episode) is made to be nothing more than the show's idea on how to attack fans of the original, going as far as to have him be in his mother's basement and have it decorated with action figures and other merchandise. While Bob, Dot, and Enzo are nice to see again, they are not done well, as this episode basically disregards events after season one and act too different.