int Player_x = 250;
int Player_y = 500;
int PlayerSpeed = 25;
int bx = 250;
int by = 500;

int BulletSpeed = 10;
int boolflying = 0;

void setup()
{
size(700,700);
}

void draw()
{
background(0);
rect(Player_x,Player_y,50,50);

if (boolflying == 1 && by > 0)
{
rect(bx,by,50,50);
by-=BulletSpeed;
}
else
{
boolflying = 0;
bx = Player_x;
by = Player_y;
}

}

void keyPressed() {
if (keyCode == UP) 
{
Player_y-=PlayerSpeed;
}
if (keyCode == DOWN) 
{
Player_y+=PlayerSpeed;  
} 

if (keyCode == LEFT) 
{
Player_x-=PlayerSpeed;
}

if (keyCode == RIGHT) 
{
Player_x+=PlayerSpeed;
}

if (keyCode == ENTER) 
{
boolflying = 1;

} 

}