Because there is no rearview mirror in most 2D versions, you must drive parallel to the opponent when they are attacking.
First, let’s clear up a common misconception. is not an official product of Psyonix (the creators of the mainstream 3D vehicular soccer blockbuster). Instead, it is a fan-made, browser-based demake that captures the essence of Rocket League —chaotic car football—using simple, two-dimensional physics.
Search for “Rocket League 2D Unblocked Games 76” in your browser to find the page hosting it. If you want a reliable experience, use a site that clearly shows controls and offers low-latency multiplayer options.