Well, i haven't read the pacman tutorial but if you have this:
namespace Game {
export let Player : PlayerBehavior;
}
you need to assign the player in your behavior.
class PlayerBehavior extends Sup.Behavior {
awake() {
Game.Player = this; // This could have been done in the start() or anywhere.
}
}
And with that you can access all the public methods or variables in your behavior using (As a side note in typescript all methods and variables are public by default)
Game.Player.jump(); // Or any other method