Meh
As my own opinion,I'd say this tutorial sucks.
First of all,you character lands on the platform after half it's body goes through.
Second,Your code has some un-needed codes,such as the gotoAndStop(2); or gotoAndStop(1); codes to make your character turn.It can be solved by _xscale = -scale or _xscale = +scale.
Third,most people like games where your character starts walking and has a jumping position and such.This tutorial is only the same figure that turns and stuff.
Fourth,hovering is a really stupid idea for a Platform Game.In your Red-Ball game,it is really easy to beat each lvl with the hover maneuver.
Fifth,when I first tried this tutorial,none of your extra codes worked(lives,hitTest).I've already made my own code.
That's all.