var Velocity = {

    setVelocityX: function (x)
    {
        this.vel.x = x;

        return this;
    },

    setVelocityY: function (y)
    {
        this.vel.y = y;

        return this;
    },

    setVelocity: function (x, y)
    {
        this.vel.x = x;
        this.vel.y = y;

        return this;
    },

    setMaxVelocity: function (x, y)
    {
        if (y === undefined) { y = x; }

        this.maxVel.x = x;
        this.maxVel.y = y;

        return this;
    }

};

module.exports = Velocity;

@@ -224,32 +224,73 @@
 on (x, y)%0A    %7B%0A
+        if (y === undefined) %7B y = x; %7D%0A%0A
         this.vel

Allow Impact.Sprite#setVelocity to accept 1 parameter