Interactivity - Spawnign waves

• open game controller script 
• add 
  
• in unity go to the game controler and change the variables of the script to this 
  
• to get rid of the asteroid explosions from the hierarchy we need to write a new code
• create a new script in the script folder called destroybytime and write 
  
• save and add this script to the  explosions prefab and make the life time 2 
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