Only assignment, call, increment, decrement, and new object expressions can be used as a statement

using UnityEngine; using System.Collections;

public class destroy : MonoBehaviour {

 public Transform killParticle;                                    // particle to play on death
 public Transform coin;                                    // coin to spawn after death
 public AudioSource[] sounds;
 public AudioSource exp;

 // Use this for initialization
 void Start () 
 {
     sounds = GetComponents<AudioSource>();
     exp = sounds[0];
     StartCoroutine (destroyMe());
 }
 
 // Update is called once per frame
 void Update () 
 {
     
 }

 void OnCollisionEnter (Collision col)
 {
     if (col.gameObject.tag == "enemy") {
         col.gameObject.GetComponent<Animation> ().CrossFade ("die");                                    // animation die    
         Instantiate (killParticle, transform.position, Quaternion.identity);            // create particle
         Instantiate (coin, transform.position, Quaternion.identity);                    // create/leave coin
         exp.Play;
         Destroy (col.gameObject, .1f);                                                        // destroy enemy
         Destroy (this.gameObject);
     } 
     else if (col.gameObject.tag == "Player") 
     {
         
     } 
     else
         exp.Play;
         Destroy (this.gameObject);

 }
 IEnumerator destroyMe()
 {
     yield return new WaitForSeconds(5f);
     Destroy (this.gameObject);

 }

}