Euclidean Plane Crash is a difficult and very fast Level in Open Hexagon. It turns quite slowly. It is the successor of Apeirogon and was the final Level until the release of V1.4, which added 3.1415926535893238462 and Golden Ratio, both of which are listed after Euclidean Plane Crash in the menu. Currently, it is the only level to feature an octagon by default as well as formerly being the only Level (excluding tutorials) to not have a definite difficulty; it is mentioned as "Special" in V1.0, which is the only hint to an official term. The lack of distinction is partially because there is no pulse, a more obvious 3D effect and a lower rotation speed than the other Levels. However, the patterns are quite unpredictable and give little warning before they come, making prolonged survival difficult.