What performance optimization can be made when handling a large number of game objects, such as 20,000 donkeys?

Replacing mesh colliders with sphere colliders is a significant performance optimization when dealing with a large number of game objects like 20,000 donkeys. Mesh colliders are complex because they must calculate collisions based on the exact shape of the mesh, which can involve intensive computations, particularly with a large number of objects.

Sphere colliders, on the other hand, are much simpler geometrically. They provide an approximate shape for collision detection that is far less resource-intensive for the physics engine to process. This means that using sphere colliders can lead to improved performance because they require far fewer calculations for collision detection compared to more complex shapes.

In scenarios where precise collision detection isn't as critical, the use of simpler colliders such as spheres can vastly enhance the game's performance, especially in environments populated with numerous objects. This optimizes the physics calculations, leading to smoother gameplay and improved frame rates.