Spatial UI elements are physically presented in the game's space. These types of UIs may or not may be visible to the other players within the game space. This is something that is particularly featured in Virtual Reality (VR) experiences. Spatial UIs are effective when you want to guide players through a level or to indicate points of interest. The following example is from Army of Two. On the ground, you can see arrows directing the player where to go next. You can find out more about implementing Spatial UIs, like the one in the following screenshot, in Unity by visiting the link to the official documentation at https://unity3d.com/learn/tutorials/topics/virtual-reality/user-interfaces-vr: