The FrontEnd is the Main Menu of Re-Volt and takes a theme of a closed toy store. This track can't be selectable in the game, except for using the DEV mode (Re-Volt 1.2). The only other way to access the frontend is by renaming all "frontend.#" files by another name, since the engine hide every level named as "frontend".
Although when playing this track, there is no collision on anything except for the floor. Also another noticeable problem with this track is that the car boxes' textures are garbled. They represent textures like the road signs. One last thing is you start in an odd position. You start on top of almost every one of your opponents. Some of the cars also start in place of the clockwork table.
Frontend appears to contain a short racing line, where cars turn around the counter of the store. Also, developers planned to create a Training mode using this track, but the idea didn't come true. This mode appears in old demos of the game.
Custom Frontends are also possible by replacing the frontend folder. One example is Sakura Frontend created by Hilaire9.