Unity – How to Change the Default Gravity
The steps listed below show you how to set your custom values for gravity in Unity (there is no difference between Windows and Mac).
1. Navigate to “Edit” > “Project Settings…” by using your mouse.
2. Select “Physic” > “Gravity” and adjust the X, Y, Z values in the corresponding fields. In the vast majority of cases, we only care about the Y value (If you are making a 2D game, then choose “Physics 2D” instead of “Physics”).
Your changes will be automatically saved and applied.