Place the frozen mango chunks, ice cubes, water, and lime juice into your blender.
Secure the lid tightly and start blending on a low speed, gradually increasing to high.
Blend for about 30-60 seconds or until the mixture becomes thick, smooth, and icy, with no large chunks remaining.
If the slushie is too thick, add a splash more water and briefly blend again. If too watery, add a few more ice cubes and blend until thickened.
Stop the blender and check the texture—it should be vibrantly colored, thick, and scoopable with a spoon.
Pour the mango slushie into chilled glasses, and garnish if desired with lime slices or fresh mint.
Serve immediately with a straw or spoon, enjoying the cold, icy burst of tropical flavor.