Actionscript 3.0 - enemies do not move right in my game
// If the Player's not on the ground (not touching the 'floor' MovieClip)...
        if (!onGround) {
            // Disable ducking
            downKeyPressed = false;
            // Increase the Player's 'y' position by his 'y' velocity
            player.y += playerYVel;
        }

        // Increase the 'playerYVel' variable so that the Player will fall
            // progressively faster down the screen. This code technically
            // runs "all the time" but in reality it only affects the player
            // when he's off the ground.
        playerYVel += gravity;

        // Give the Player a terminal velocity of 15 px/frame
        if (playerYVel > 15) {
            playerYVel = 15;
        }

        // If the Player has not hit the 'floor,' increase his falling
            //speed
        if (! floor.hitTestPoint(player.x, player.y, true)) {
            player.y += playerYVel;
            // The Player is not on the ground when he's not touching it
            onGround = false;
        }

// Move all of the Skull Demons using this method
    protected function moveSkullDemons():void {
        // Go through the whole 'skullDemonContainer'
        for (var skullDi:int = 0; skullDi < skullDemonContainer.numChildren; skullDi++) {
            // Set the SkullDemon 'instance' variable to equal the current SkullDemon
            skullDIns = SkullDemon(skullDemonContainer.getChildAt(skullDi));

            // For now, just move the Skull Demons left at 5 units per second
            skullDIns.x -= 5;

            // If the Skull Demon has not hit the 'floor,' increase his falling
                //speed
            if (! floor.hitTestPoint(skullDIns.x, skullDIns.y, true)) {
                // Increase the Skull Demon's 'y' position by his 'y' velocity
                skullDIns.y += skullDIns.sdYVel;
                // The Skull Demon is not on the ground when he's not touching it
                skullDIns.sdOnGround = false;
            }

            // Increase the 'sdYVel' variable so that the Skull Demon will fall
                // progressively faster down the screen. This code technically
                // runs "all the time" but in reality it only affects the Skull Demon
                // when he's off the ground.
            if (! skullDIns.sdOnGround) {
                skullDIns.sdYVel += skullDIns.sdGravity;

                // Give the Skull Demon a terminal velocity of 15 px/frame
                if (skullDIns.sdYVel > 15) {
                    skullDIns.sdYVel = 15;
                }
            }

            // What happens when the Skull Demon lands on the ground after a fall?
                // The Skull Demon is only on the ground ('onGround == true') when
                    // the ground is touching the Skull Demon MovieClip's origin point,
                    // which is at the Skull Demon's bottom centre
            for (var i:int = 0; i < 10; i++) {
                // The Skull Demon is only on the ground ('onGround == true') when
                    // the ground is touching the Skull Demon MovieClip's origin point,
                    // which is at the Skull Demon's bottom centre
                if (floor.hitTestPoint(skullDIns.x, skullDIns.y, true)) {
                    skullDIns.y = skullDIns.y;
                    // Set the Skull Demon's y-axis speed to 0
                    skullDIns.sdYVel = 0;
                    // The Skull Demon is on the ground again
                    skullDIns.sdOnGround = true;
                }
            }
        }
    } // End of 'moveSkullDemons()' function