Tilt-a-Kart is a battle course in Mario Kart: Double Dash!! The course is a large platform that forms out the original 8-bit pixelated form of Mario, with the color palette that he had in Super Mario Bros., a concept later used on the 8-bit planet in the Toy Time Galaxy from Super Mario Galaxy and Mario Squared Galaxy from Super Mario Galaxy 2. The battle course also has a background that somewhat resembles that of the special stages from Super Mario Sunshine. Its name is likely a reference to the Tilt-A-Whirl type of amusement park equipment.
As the name implies, the course tilts side-to-side, hindering the battle. White tiles surrounding Mario's figure can slow down the Karts, making them easy targets for being hit by items. Additionally, when players fall off (this being the only battle course in the game to have this possible), they are placed on small white platforms above the Tilt-a-Kart, which they are forced to drive off of and onto the course, much like Mario Bros. when the player(s) lose a life as they restart on a small platform above the stage and resume gameplay by jumping off it. Like those in Daisy Cruiser, Item Boxes tilt around on the stage as the stage itself does.
This course is unlockable, and is unlocked when the Flower Cup is beaten in Mirror Mode, making it the last battle course to be unlocked. The music in this course is somewhat based on that of the Super Mario Bros. main theme and Baby Park (although it is essentially the same tune), yet there are slight differences in the music. There are more cymbals, and the instrument that plays the chords is different, as well as being in a lower inversion. In Shine Thief, the standard battle music is used.