Alright - let's start changing this platformer into a horizontal shooter, and talk a bit about a few common places we can optimize scripts for this type of game! Note: as stated in the video itself, these tutorial modules are prone to small bugs and issues. They are not designed to be robust enough to create commercial quality games as they are. But they are great starting points for understanding how these games can work, and get you creating and experimenting quickly!
Here's the new tutorial and instructions (with the link the "Support Files" zip):