var yPos = [];

var blues = [];

var speeds = [];

var l = 0.5;

var m = 7.5;

function setup() {

  createCanvas(400, 400);

  var count = 0;

  while (count < 750){

  append(xPos,random(400));

  append(yPos,random(400));

  append(speeds,random(l,m));

    frameRate(10);

    count++;

  }

  noStroke();

}

​

function draw() {

  background(0,0,0);

  fill(0,0,255);

  var i = 0;

  while(i < xPos.length){

    fill(0,244,0);

  //ellipse(xPos[i],yPos[i],5,5);

     text(char(random(913,1024)),xPos[i],yPos[i]);

    yPos[i] = yPos[i] + speeds[i];

       if (key === 'w'){

  yPos[i] = yPos[i] - speeds[i]*2;

}

       if (key === 's'){

 yPos[i] = yPos[i] + speeds[i]/2;

}

    if(yPos[i] > 400){

    yPos[i] = 0;

}

    if(yPos[i] < 0){

    yPos[i] = 400;

}

     i++;

  }

}