TO SQUASH: added basic balls.

Assets/Scripts/Game/BallSpawner.cs

@@ -0,0 +1,86 @@
+using UnityEngine;
+using System.Collections;
+using System.Collections.Generic;
+
+public class BallSpawner : MonoBehaviour
+{
+    public GameObject basicBallPrefab;
+
+    public GameObject nuclearBallPrefab;
+
+    public GameObject glassBallPrefab;
+
+    public GameObject eyeBallPrefab;
+
+    public GameObject oozeBallPrefab;
+
+    public GameObject fruitBallPrefab;
+
+    public GameObject gameBoard;
+
+    private static WaitForSeconds _waitForSeconds0_5 = new WaitForSeconds(0.5f);
+
+    private Queue<System.Action> ballQueue = new Queue<System.Action>();
+
+    // Start is called once before the first execution of Update after the MonoBehaviour is created
+    void Start()
+    {
+        int currentLevel = PlayerPrefs.GetInt("CurrentLevel");
+
+        ballQueue.Enqueue(() => SpawnBasicBall());
+        ballQueue.Enqueue(() => SpawnBasicBall());
+        ballQueue.Enqueue(() => SpawnBasicBall());
+        ballQueue.Enqueue(() => SpawnBasicBall());
+
+        StartCoroutine(SpawnBalls());
+    }
+
+    private void SpawnBasicBall()
+    {
+        if (basicBallPrefab == null || gameBoard == null)
+        {
+            Debug.LogWarning("BallSpawner: Missing basicBallPrefab or gameBoard reference.");
+            return;
+        }
+
+        Vector3 spawnPosition = GetRandomPositionInsideGameBoard();
+        Instantiate(basicBallPrefab, spawnPosition, Quaternion.identity);
+    }
+
+    private Vector3 GetRandomPositionInsideGameBoard()
+    {
+        Bounds bounds;
+
+        Collider2D collider2D = gameBoard.GetComponent<Collider2D>();
+        if (collider2D != null)
+        {
+            bounds = collider2D.bounds;
+        }
+        else
+        {
+            Renderer boardRenderer = gameBoard.GetComponent<Renderer>();
+            if (boardRenderer == null)
+            {
+                Debug.LogWarning("BallSpawner: gameBoard needs a Collider2D or Renderer to read bounds.");
+                return gameBoard.transform.position;
+            }
+
+            bounds = boardRenderer.bounds;
+        }
+
+        float randomX = Random.Range(bounds.min.x, bounds.max.x);
+        float randomY = Random.Range(bounds.min.y, bounds.max.y);
+
+        return new Vector3(randomX, randomY, gameBoard.transform.position.z);
+    }
+
+    private IEnumerator SpawnBalls()
+    {
+        while (ballQueue.Count > 0)
+        {
+            System.Action spawnAction = ballQueue.Dequeue();
+            spawnAction.Invoke();
+            yield return _waitForSeconds0_5;
+        }
+    }
+}

Assets/Scripts/Game/BallSpawner.cs.meta

@@ -0,0 +1,2 @@
+fileFormatVersion: 2
+guid: b45a86a9500699daf8af02a61c756b2b

Assets/Scripts/Game/Balls.meta

@@ -0,0 +1,8 @@
+fileFormatVersion: 2
+guid: 1b9d11fbe5aebe016b8940bc88822ac2
+folderAsset: yes
+DefaultImporter:
+  externalObjects: {}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/Scripts/Game/Balls/BasicBall.cs

@@ -0,0 +1,45 @@
+using UnityEngine;
+
+public class BasicBall : MonoBehaviour
+{
+    private Animator animator;
+
+    public AudioClip spawnSound;
+
+    public AudioClip bounceSound;
+
+    public AudioClip hitSound;
+
+    private AudioSource audioSource;
+
+    private Vector2 speed;
+
+    // Start is called once before the first execution of Update after the MonoBehaviour is created
+    void Start()
+    {
+        audioSource = GetComponent<AudioSource>();
+        animator = GetComponent<Animator>();
+        speed = new Vector2(Random.Range(-0.05f, 0.05f), Random.Range(-0.05f, 0.05f));
+
+        audioSource.PlayOneShot(spawnSound);
+    }
+
+    // Update is called once per frame
+    void FixedUpdate()
+    {
+        AnimatorStateInfo stateInfo = animator.GetCurrentAnimatorStateInfo(0);
+
+        if (stateInfo.IsName("BasicBallMove")) {
+            transform.Translate(speed);
+        }
+    }
+
+    void OnCollisionEnter2D(Collision2D collision)
+    {
+        if (collision.gameObject.CompareTag("Wall") || collision.gameObject.CompareTag("Ball"))
+        {
+            ContactPoint2D contact = collision.GetContact(0);
+            speed = Vector2.Reflect(speed, contact.normal);
+        }
+    }
+}

Assets/Scripts/Game/Balls/BasicBall.cs.meta

@@ -0,0 +1,2 @@
+fileFormatVersion: 2
+guid: 5788fcee29b49660abecc58bc2095706

Assets/Scripts/Game/MusicManager.cs

@@ -1,6 +1,7 @@
 using UnityEngine;
 using System.Collections.Generic;
 
+// Idea from https://discussions.unity.com/t/play-audio-in-queue/239402/2
 public class MusicManager : MonoBehaviour
 {
     public AudioClip intro;