Spaceship

Changes :

Added one png file of a pixel heart which was uploaded on 3 images which where placed on the top-right corner of the canvas , these images where added the DestroyOnTrigger2D.sc input fields which are being destroyed when player makes a mistake .

On DestroyOnTrigger2D.sc file added a hit counter which also controls the show-up of the life bars one the screen.

On Mover.cs file added a function that registers a collision between a laser shot from the spaceship and the enemy object.