Spawning enemies
To make the level fun and challenging, we'll need more than simply one enemy. In fact, for a game that's essentially endless, we'll need to add enemies continually and gradually over time. Essentially, we'll need either regular or intermittent spawning of enemies, and this section will add that functionality. Before we can do this, however, we'll need to make a prefab from the enemy object. The steps are the same as for previously created prefabs: select the enemy in the Hierarchy panel and then drag and drop it to the Project panel in the Prefabs folder:
Figure 3.28 – Creating an enemy prefab
Now, we'll make a new script, called Spawner.cs, that spawns new enemies in the scene over time within a specified radius from the player spaceship. This script should be attached to a new, empty GameObject in the scene:
public class Spawner : MonoBehaviour
{
public float MaxRadius = 1f;...