My player falls really slowly and cant jump

I recently got the version of unity for playstation mobile to try and make one of my other games on it I copied and pasted a script but my player wouldnt jump even though the animation was playing and he fell really slowly. My script (sorry it is so long): #pragma strict

 //VARIABLES
 var health : int = 5;
 var Speed : float = 12;
 var Health : float = 100;
 var JumpHeight : float = 15;
 var Skin : GUISkin;
 var AbilityLabelTime : float = 3;
 var Dave : Animator;
 var CanShoot : boolean = true;
 var ShootTakeTime : float = 2;
 
 //Animator Variables
 Dave.SetBool("Jumping", false);
 Dave.SetBool("CollectedSB", false);
 Dave.SetBool("CollectedG", false);
 Dave.SetBool("CollectedMB", false);
 Dave.SetBool("CollectedGevar", false);
 Dave.SetBool("RLEquiped", false);
 
 //Items and ability variables
 var ShowLabelSuperboots : boolean = false;
 var ShowLabelLaserblaster : boolean = false;
 var ShowLabelMegaBoots : boolean = false;
 var ShowLabelGevar : boolean = false;
 var ShowLabelRocketLauncher : boolean = false;
 
 //Collection variables
 var CollectedGun : boolean = false;
 var CollectedSuperboots : boolean = false;
 var CollectedMegaboots : boolean = false;
 var CollectedGevar : boolean = false;
 var CollectedRocketLauncher : boolean = false;
 var RLEquiped : boolean = false;
 var StopTime : float = 3;
 var canJump : boolean = true;
 
 
 //Jump height variables
 var JumpLow : float = 15;
 var JumpMedium : float = 28.5;
 var JumpHigh : float = 38.5;
 
 //Bullet variables
 public var bulletRight : GameObject;
 public var bulletLeft : GameObject;
 public var RocketRight : GameObject;
 public var RocketLeft : GameObject;
 
 function Start () {
 
 }
 
 function Update () 
 {
 
     if (health <= 0) {
         Dead ();
     }
 
     
 
 
 //Jump
 if(Input.GetKey("w") && canJump){
     this.rigidbody2D.velocity.y += JumpHeight;
     Dave.SetBool("Jumping", true);
     canJump = false;
 }
 //Move left
 if (Input.GetKey (KeyCode.A)) 
     {
         transform.localScale.x = 1;
         transform.Translate(Vector3(-Speed,0,0) * Time.deltaTime);
     }
     
 //Move right
 if (Input.GetKey (KeyCode.D)) 
     {
         transform.localScale.x = 1;
         transform.Translate(Vector3(Speed,0,0) * Time.deltaTime);
     }
      
 //Shoot right     
 if (CollectedGun == true && RLEquiped == false){ 
      if(Input.GetKey(KeyCode.RightArrow)) { 
          Instantiate(bulletRight, transform.position, Quaternion.identity);
     }
 }
     
 //Shoot left    
          if (CollectedGun == true && RLEquiped == false){ 
       if (Input.GetKey(KeyCode.LeftArrow)) {
           Instantiate(bulletLeft, transform.position, Quaternion.identity);
         }
     }
     
 //Turning rockets on/off
     if (CollectedRocketLauncher == true && RLEquiped == false && Input.GetKeyDown(KeyCode.R)){
               RLEquiped = true;
               Dave.SetBool("RLEquiped", true);
               gameObject.Find("Rocket").SendMessage("On");
               gameObject.Find("Bullet").SendMessage("Off");
  }
  
 else if (CollectedRocketLauncher == true && RLEquiped == true && Input.GetKeyDown(KeyCode.R)){
               RLEquiped = false;
               Dave.SetBool("RLEquiped", false);
               gameObject.Find("Rocket").SendMessage("Off");
               gameObject.Find("Bullet").SendMessage("On");
  }
     
 //Shoot rocket right    
       if (CollectedRocketLauncher == true && RLEquiped == true && CanShoot == true){
           if (Input.GetKey(KeyCode.RightArrow)){
               Instantiate(RocketRight, transform.position, Quaternion.identity);
               CanShoot = false;
               WaitForShoot ();
           }
       }
       
 //Shoot rocket left
       if (CollectedRocketLauncher == true && RLEquiped == true && CanShoot == true){
         if (Input.GetKey(KeyCode.LeftArrow)){
             Instantiate(RocketLeft, transform.position, Quaternion.identity);
             CanShoot = false;
               WaitForShoot ();
         }
       }
 
 
 
 // JUMPING HEIGHTS
 //Low Jump      
     if (Input.GetKey(KeyCode.Z)){      
               JumpHeight = JumpLow;
                   gameObject.Find("High").SendMessage("Off");
                   gameObject.Find("Medium").SendMessage("Off");
                 gameObject.Find("Low").SendMessage("On");
       }
 
 //Medium Jump    
       if (CollectedSuperboots == true){
               if (Input.GetKey(KeyCode.X)){
               JumpHeight = JumpMedium;
                   gameObject.Find("High").SendMessage("Off");
                   gameObject.Find("Medium").SendMessage("On");
                   gameObject.Find("Low").SendMessage("Off");
           }
       }      
 
 //High Jump     
       if (CollectedMegaboots == true){
           if (Input.GetKey(KeyCode.C)){
               JumpHeight = JumpHigh;
                   gameObject.Find("High").SendMessage("On");
                   gameObject.Find("Medium").SendMessage("Off");
                 gameObject.Find("Low").SendMessage("Off");
           }
       }
 
 }
 
 function OnTriggerEnter2D (other : Collider2D) {
 
  //POWER UPS / ITEMS 
 //Super speed power up
      if (other.gameObject.tag == "SuperSpeed") {    
           ShowLabelSuperboots = true;
          Speed = Speed + 8;
          CollectedSuperboots = true;
          Dave.SetBool("CollectedSB", true);
          WaitAndFalseSuperSpeed ();
          Destroy(other.gameObject);
      }
      
 //Laserblaster power up     
      if (other.gameObject.tag == "Laserblaster") {
          CollectedGun = true;
          Dave.SetBool("CollectedG", true);
          gameObject.Find("Rocket").SendMessage("Off");
           gameObject.Find("Bullet").SendMessage("On");
          ShowLabelLaserblaster = true;
          WaitAndFalseLaserblaster ();
          Destroy(other.gameObject);        
      }
      
 //Megaspeed power up     
      if (other.gameObject.tag == "MegaSpeed") {
          ShowLabelMegaBoots = true;
         Speed = Speed + 10;
         Dave.SetBool("CollectedMB", true);
         CollectedMegaboots = true;
         WaitAndFalseMegaBoots ();
         Destroy(other.gameObject);                 
      }
      
 //Gevar suit power up     
      if (other.gameObject.tag == "Gevar") {
          ShowLabelGevar = true;
          Dave.SetBool("CollectedGevar", true);
          CollectedGevar = true;
          WaitAndFalseGevar ();
          Destroy(other.gameObject);
      }
 
 //Rocket launcher power up     
       if(other.gameObject.tag == "RocketLauncher") {
           ShowLabelRocketLauncher = true;
           CollectedRocketLauncher = true;
           WaitAndFalseRL ();
           Destroy(other.gameObject);
       }
 
 
                
      if (other.gameObject.tag == "Lava" && CollectedGevar == false) {
          Health -= 10000000000000;
      }
  }
 
 function WaitForShoot () {
     yield WaitForSeconds(ShootTakeTime); CanShoot = true;
 }
   
  function OnGUI()  {
      GUI.skin = Skin;
      
      //LABLES AND GUI
      
      
      //Label Super Boots
      if (ShowLabelSuperboots){
           GUI.Label(Rect(100,100,Screen.width,Screen.height),"Super Boots Acquired - These let you move and jump faster, press X to activate, press Z to jump normally again"); 
       }
       
       //Label Laserblaster
       if (ShowLabelLaserblaster){
           GUI.Label(Rect(100,100,Screen.width,Screen.height),"Laser Blaster Acquired - This lets you shoot, left arrow to shoot left, right arrow to shoot right");
       }
       
       //Label Mega Boots
       if (ShowLabelMegaBoots){
           GUI.Label(Rect(100,100,Screen.width,Screen.height),"Mega Boots Acquired - These let you move and jump even faster, press C to use it");
       }
       
       //Label Gevar Suit
       if (ShowLabelGevar){
           GUI.Label(Rect(100,100,Screen.width,Screen.height),"Gevar Suit Acquired - Protects you from lava");
       }
       
       //Label Rocket Launcher
       if (ShowLabelRocketLauncher) {
           GUI.Label(Rect(100,100,Screen.width,Screen.height),"Rocket Launcher Acquired - Press R to switch to rockets press again to switch back");
       }
  }
 
  //Function Super Speed
  function WaitAndFalseSuperSpeed () {
      yield WaitForSeconds(AbilityLabelTime); ShowLabelSuperboots = false;
  } 
  
  //Function Laserblaster
  function WaitAndFalseLaserblaster () {
      yield WaitForSeconds(AbilityLabelTime); ShowLabelLaserblaster = false;
  }
  
  //Function Megaboots
  function WaitAndFalseMegaBoots () {
      yield WaitForSeconds(AbilityLabelTime); ShowLabelMegaBoots = false;
  }
  
  //Function Gevar
  function WaitAndFalseGevar () {
      yield WaitForSeconds(AbilityLabelTime); ShowLabelGevar = false;
  }
  
  //Function Rocket Launcher
  function WaitAndFalseRL () {
      yield WaitForSeconds(AbilityLabelTime); ShowLabelRocketLauncher = false;
  }
  
  //GROUND DETECTOR
  function OnCollisionEnter2D (other : Collision2D) {
      if(other.transform.tag == "Ground"){
         canJump = true;
         Dave.SetBool("Jumping", false);
      }
           if(other.gameObject.tag == "Enemy") {
          health -= 1;
      }
  }
  
  function Dead () 
 {
     Destroy(gameObject);
 }