Paper.io 2 takes place on a sphere, not a flat map. The mini map helps you navigate the "edges."
If several enemy dots converge on one spot on the mini-map, they’re either fighting or someone just died—that’s a prime time to move in. paper.io 2 mini map
Your own tail is visible on the mini-map as a line extending from your dot. If it gets too long and you see another dot approaching it, turn back. paper.io 2 mini map