seek.js

var distance = this.distanceTo(this.target),
    d = this.angleTo(this.target),
    steerX = Math.cos(d),
    steerY = Math.sin(d),
    newX = (this.target.pos.x + distance / this.target.vel.x) - this.pos.x,
    newY = (this.target.pos.y + distance / this.target.vel.y) - this.pos.y,
    // keep speed 10 or less
    speed = Math.min(distance, 30) / 6;
this.vel.x += steerX * speed;
this.vel.y += steerY * speed;
            
            
// method 2
this.maxVel= {x: 500, y: 500};
this.speed = 20000;
var centerX = this.pos.x + (this.size.x - (this.size.x / 2)),
    centerY = this.pos.y + (this.size.y - (this.size.y / 2)),
    targetCenterX = this.target.pos.x + this.target.size.x / 2,
    targetCenterY = this.target.pos.y + this.target.size.y / 2,
    diffX = creepCenterX - pCenterX,
    diffY = creepCenterY - pCenterY,
    currSpeed = (diffX * diffX) + (diffY * diffY),
    cFact = this.speed / currSpeed;

this.vel.x = Math.sqrt(cFact) * diffX;
this.vel.y = Math.sqrt(cFact) * diffY;