Most versions of the 2D game store your browser's local storage for high scores. Here is how to cheese the system:

Rocket League 2D brings the high-energy car-soccer action of the original Rocket League into a lightweight, browser-friendly 2D format. Perfect for quick matches between classes or during breaks, it’s easy to learn, hard to master, and completely free to play on Unblocked Games 66.

Rocket League 2D on Unblocked Games 66 is a fan-made, side-scrolling adaptation of the popular car-soccer title, designed to bypass network filters in school or work environments. The HTML5 browser game features 2D physics, local two-player modes, and core mechanics like boosting and aerial stunts, with popular versions developed by creators such as Gurpreet Singh Matharoo. For more, visit Unblocked Games 66 . Unblocked Games 66 - Unblocked Games for School - Google