Ho modificato il programma di challenge pong di "Making a side scroller: Hoppy Beaver" nell'unità 4 di javascript in modo da far muovere entrambe le racchette con i comandi SU, GIÙ, CONTROLLO e MAIUSC ma mentre premo il pulsante per muovere una paletta l'altra non si muove, cosa posso fare?

var player1Y = altezza/2;
var player2Y = altezza/2;
var player1Score = 0;
var player2Score = 0;
palla var;
var gameStarted = false;
var t = 0;

Costanti
var PAUSE_TIME = 60000000;
var PLAYER_MOVE_SPEED = 3;
var BALL_SPEED = 2,5;
var PADDLE_HEIGHT = 100;
var PADDLE_WIDTH = 20;

angleMode = "gradi";

var Ball = function(posizione, velocità) {
this.position = posizione;
this.speed = velocità || BALL_SPEED;

this.radius = 12;

this.resetVelocity = function() {
this.theta = random(0, 360);
this.velocity = new PVector(
this.speed*cos(this.theta), -this.speed*sin(this.theta));
player2Y = height/2;
};
this.resetVelocity();

this.draw = function() {
fill(255, 255, 255);
noStroke();
ellipse(this.position.x, this.position.y,
this.radius*2, this.radius*2);
if(keyIsPressed && keyCode === UP){}
};

this.collideWithPaddle = function(x, y) {
if (this.position.x - this.radius < x + PADDLE_WIDTH/2 &&
this.position.x + this.radius > x - PADDLE_WIDTH/2) {
if (dist(0, this.position.y, 0, y)
< PADDLE_HEIGHT/2 + this.radius) {
if (this.position.x > x) {
this.position.x = x +
this.radius + PADDLE_WIDTH/2;
}
else if (this.position.x < x) {
this.position.x = x -
this.radius - PADDLE_WIDTH/2;
}
this.velocity.mult(new PVector(-1, 1));
}
}
};

this.update = function() {
//Gestisci le collisioni sui muri
if (this.position.x < 0) {
player2Score++;
this.position = new PVector(width/2, height/2);
gameStarted = false;
this.resetVelocity();
}
else if (this.position.x > width) {
player1Score++;
this.position = new PVector(width/2, height/2);
gameStarted = false;
this.resetVelocity();
}
if (this.position.y < 0) {
this.position.y = 0;
this.velocity.mult(new PVector(1, -1));
}
else if (this.position.y > height) {
this.position.y = height;
this.velocity.mult(new PVector(1, -1));
}

//Gestisci le collisioni con la
paletta this.collideWithPaddle(20, player1Y);
this.collideWithPaddle(larghezza-20, player2Y);

this.position.add(this.velocity);
    };
};

ball = new Ball(new PVector(width/2, height/2));

var drawScores = function() {
    var s;
    
    fill(255, 255, 255);
    textSize(20);
    
    s = "Player 1: " + player1Score;
    text(s, width*0.25-textWidth(s)/2, 25);
    s = "Player 2: " + player2Score;
    text(s, width*0.75-textWidth(s)/2, 25);
};

/*var updatePlayer2 = function() {
    if (abs(player2Y-ball.position.y) < PLAYER_MOVE_SPEED){
        player2Y = ball.position.y;
    }
    else if (player2Y-ball.position.y >= PLAYER_MOVE_SPEED) {
        player2Y -= PLAYER_MOVE_SPEED;
    }
    else if (player2Y-ball.position.y <= PLAYER_MOVE_SPEED) {
        player2Y += PLAYER_MOVE_SPEED;
    }
    
};*/

//Move the player up

var movePlayer1Up = function() {
    player1Y -= PLAYER_MOVE_SPEED;
    
};
var movePlayer2Up = function() {
    player2Y -= PLAYER_MOVE_SPEED;
    
};

//Move the player down

var movePlayer1Down = function() {
    player1Y += PLAYER_MOVE_SPEED;
};
var movePlayer2Down = function() {
    player2Y += PLAYER_MOVE_SPEED;
};

var drawPlayers = function() {
    //Constrain the player movement
    player1Y = constrain(player1Y, 0,400);
    
    rectMode(CENTER);
    fill(255, 255, 255);
    rect(20, player1Y, PADDLE_WIDTH, PADDLE_HEIGHT);
    rect(width-20, player2Y, PADDLE_WIDTH, PADDLE_HEIGHT);
    player2Y = constrain(player2Y, 0,400);
    
    rectMode(CENTER);
    fill(255, 255, 255);
    rect(20, player2Y, PADDLE_WIDTH, PADDLE_HEIGHT);
    rect(width-20, player2Y, PADDLE_WIDTH, PADDLE_HEIGHT);
};
draw= function() {
    //Control Player 2
    if(keyIsPressed){
    if (keyCode===SHIFT) {
    movePlayer2Up();
    }}
    if(keyIsPressed){
    if (keyCode===CONTROL) {
    movePlayer2Down();
    }}
};

draw = function() {
//Control Player 1
if(keyIsPressed){
if (keyCode===UP) {
movePlayer1Up();

}
if (keyCode===GIÙ) {
movePlayer1Down();
}
}
//Disegna lo sfondo dell'ambiente
(0, 0, 0);
//updatePlayer2();
disegnareGiocatori();
drawScores();
corsa(255, 255, 255);
linea(larghezza/2, 0, larghezza/2, altezza);

//Disegna la palla
ball.draw();

if (!gameStarted) {
t++;
if (t >= PAUSE_TIME) {
t = 0;
gameStarted = true;
}
ritorno;
    }

    ball.update();
};