TO SQUASH: Started shark.

Assets/Scripts/Game/Shark.cs

@@ -1,16 +1,107 @@
 using UnityEngine;
+using System.Collections;
 
 public class Shark : MonoBehaviour
 {
+    public AudioClip spawnSound;
+
+    public AudioClip angrySound;
+
+    public AudioClip tiredSound;
+
+    public AudioClip deathSound;
+
+    public Player player;
+
+    private AudioSource audioSource;
+
+    private Animator animator;
+
+    private int angle = 0;
+
+    private bool isAngry = false;
+
+    private bool isTired = false;
+
+    private bool isDead = false;
+
+    private float angryTimer = 0f;
+
+    private float angryDuration = 5f;
+
+    private float angryProbability = 0.1f;
+
+    private static int sharkKillPoints = 100;
+
     // Start is called once before the first execution of Update after the MonoBehaviour is created
     void Start()
     {
-        
+        audioSource = GetComponent<AudioSource>();
+        animator = GetComponent<Animator>();
+
+        bool spawnLeft = Random.Range(0, 2) == 0;
+        angle = spawnLeft ? 90 : 270;
+
+        animator.SetBool("spawnLeft", spawnLeft);
+        audioSource.PlayOneShot(spawnSound);
     }
 
     // Update is called once per frame
-    void Update()
+    void FixedUpdate()
     {
-        
+        // Do stuff only if the spawn animation is finished
+        if (
+            (animator.GetCurrentAnimatorStateInfo(0).IsName("SharkSpawnRight") ||
+            animator.GetCurrentAnimatorStateInfo(0).IsName("SharkSpawnLeft")) &&
+            animator.GetCurrentAnimatorStateInfo(0).normalizedTime >= 1.0f
+        )
+        {
+            // TODO: Check if the shark was killed.
+
+
+            if (isDead)
+            {
+                animator.SetTrigger("killed");
+                audioSource.PlayOneShot(deathSound);
+                // TODO: award points to the player.
+                player.score += sharkKillPoints;
+                StartCoroutine(DestroyShark());
+            } 
+            else
+            {
+                // TODO: Compute movement position and update the shark's speed and angle.
+                // TODO: Apply 2x movement speed if the shark is angry.
+                animator.SetInteger("angle", angle);   
+
+                if (!isAngry && !isTired && Random.value < angryProbability)
+                {
+                    isAngry = true;
+                    angryTimer = angryDuration;
+                    audioSource.PlayOneShot(angrySound);
+                }
+
+                if (isAngry && !isTired && angryTimer <= 0f)
+                {
+                    isAngry = false;
+                    isTired = true;
+                    audioSource.PlayOneShot(tiredSound);
+                }
+
+                if (isAngry)
+                {
+                    angryTimer -= Time.fixedDeltaTime;
+                }
+            }
+        }
+    }
+
+    private IEnumerator DestroyShark()
+    {
+        // Wait two loops of the death animation before destroying the shark object.
+        yield return new WaitUntil(
+            () => animator.GetCurrentAnimatorStateInfo(0).IsName("SharkDeath") && 
+                  animator.GetCurrentAnimatorStateInfo(0).normalizedTime >= 2.0f
+        );
+        Destroy(gameObject);
     }
 }

Assets/Scripts/Game/SharkSpawner.cs

@@ -1,16 +0,0 @@
-using UnityEngine;
-
-public class SharkSpawner : MonoBehaviour
-{
-    // Start is called once before the first execution of Update after the MonoBehaviour is created
-    void Start()
-    {
-        
-    }
-
-    // Update is called once per frame
-    void Update()
-    {
-        
-    }
-}

Assets/Scripts/Game/Spawners.meta

@@ -0,0 +1,8 @@
+fileFormatVersion: 2
+guid: 9b8a711988d7bf908bb986ce809a84bb
+folderAsset: yes
+DefaultImporter:
+  externalObjects: {}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/Scripts/Game/Spawners/SharkSpawner.cs

@@ -0,0 +1,60 @@
+using UnityEngine;
+
+public class SharkSpawner : MonoBehaviour
+{
+    public GameObject sharkPrefab;
+
+    public SpriteRenderer gameBoardSpriteRenderer;
+
+    private Bounds sharkBounds;
+
+    private Bounds gameBoardBounds;
+
+    private float spawnTimer = 0f;
+
+    private Vector2 spawnPosition;
+
+    private bool isActive = true;
+
+    private static float spawnProbability = 0.1f;
+
+    // Start is called once before the first execution of Update after the MonoBehaviour is created
+    void Start()
+    {
+        gameBoardBounds = gameBoardSpriteRenderer.bounds;
+        sharkBounds = sharkPrefab.GetComponent<SpriteRenderer>().bounds;
+        Reset();
+    }
+
+    // Update is called once per frame
+    void FixedUpdate()
+    {
+        spawnTimer += Time.fixedDeltaTime;
+
+        if (spawnTimer >= 1f && isActive)
+        {
+            spawnTimer = 0f;
+            if (Random.value < spawnProbability)
+            {
+                GameObject shark = Instantiate(sharkPrefab, spawnPosition, Quaternion.identity);
+                isActive = false;
+            }
+        }
+    }
+
+    public void Reset()
+    {
+        isActive = true;
+        spawnTimer = 0f;
+        spawnPosition = new Vector2(
+            Random.Range(
+                gameBoardBounds.min.x + sharkBounds.extents.x, 
+                gameBoardBounds.max.x - sharkBounds.extents.x
+            ),
+            Random.Range(
+                gameBoardBounds.min.y + sharkBounds.extents.y, 
+                gameBoardBounds.max.y - sharkBounds.extents.y
+            )
+        );
+    }
+}