All my sprites are rendering perfectly in correct order using the layer/sorting system on the same z-axis - in accordance with Unity's own recommended approach to 2D rendering - and OnMouseEnter works perfectly on each of them individually when they're separated. But when they are close together & overlap, OnMouseEnter/Over is not able to determine the correct collider to use. So I often get rear objects running the OnMouseEnter code incorrectly. Is there an obvious solution to this that I'm missing? It seems strange that there is no built in function for a 2D-OnMouse event to look at multiple colliders on the same Z-axis & then simply check the Y position to determine which is the correct gameobject. Surely detecting overlapping fore/rear sprites with the pointer correctly is a fundamental necessity in 2D game development? Is there no built-in way to do this?