Runner_Iceland_2019/Assets/SledgeBoost.cs

using UnityEngine;
using System.Collections;

public class SledgeBoost : MonoBehaviour
{
    private static SledgeBoost _instance;
    // Use this for initialization
    void Start ()
    {
        _instance = this;
        gameObject.SetActive(false);
	}
	
	// Update is called once per frame
	void Update () {
	
	}

    public static void Boost()
    {
        if (!_instance)
        {
            return;
        }
        _instance.gameObject.SetActive(true);
        _instance.StartCoroutine(_instance.BoostRoutine());
    }

    private IEnumerator BoostRoutine()
    {
        
        for (int i = 0; i < 20; i++)
        {
            Time.timeScale += 0.05f;
            yield return new WaitForSeconds(0.1f);
        }
        yield return new WaitForSeconds(6f);

        for (int i = 0; i < 20; i++)
        {
            Time.timeScale -= 0.05f;
            yield return new WaitForSeconds(0.1f);
        }

        Time.timeScale = 1f;
        gameObject.SetActive(false);
    }
}