Start a new Scratch project - "File" and then "New"
Replace the cat sprite with the "SpaceShip" sprite in the folder "Asteroids". You will find the "Asteroids" folder in the usual place in the Student share.
Make the stage the blackness of deep space.
Use the traditional controls to make the space ship turn left and right.
Add a small white dot as a missile.
Next add the motion to the missile. This introduces the "position of" block as shown in the image.1. Screenshot your project so far and describe how you added the spaceship and all of its code.
Add the largest asteroid from the folder and give it the motion as shown in the image. The idea of the game is that when the asteroid passes out of view it will continue its journey in the same direction from the opposite side of the screen
Add the other smaller asteroids as costumes to the larger asteroid.
Add another thread that will change costume when the asteroid is hit by the missile.
Duplicate the asteroid so that there are now 4 of them.2. Screenshot your project so far and describe how you added all of the asteroids.
Duplicate the spaceship costume and break it apart a little.
Repeat this a few more times so that when the spaceship is struck by an asteroid it sort of comes apart.
Add a thread that changes the costume in sequence when the asteroid strikes the spaceship.
This is all well and good, but you would need to write a thread for each asteroid striking the space ship. An easier way is to get the asteroid to detect the ship and broadcast a value such as "hit" and then get the ship to break apart when it receives the broadcast "hit".3. Screenshot your project so far and describe how you arranged for the spaceship to be destroyed by an asteroid.
This is the working game although there are a few little issues to clear up. First, when the missile hits an asteroid it continues still hitting the asteroid so one shot is usually enough. Change this so that the asteroids has to be hit by different missiles to be destroyed. Second, in the real game when the asteroid is struck it splits in to two so there will be two middle sizes asteroids and then each if these will divide into two. Thirdly the asteroids get faster as they get smaller.4. Screenshot your project so far and describe how you added At least one of the improvements given above.
The arcade game also had an interesting way of moving the spaceship. As there is no gravity it behaves like a free body, i.e. if there is no acceleration then it continues in the same direction at the same velocity. It has the same limitation as an asteroid in that if it goes off the screen then it reappears on the opposite side.5. Screenshot your project so far and describe how you added all of the improvements given above in both extensions