Space Blaster - Tutorial

Usage of spawners- If you just place down a few spawners, this would not constitute as a significant change. 

More usage of environment (asteroids) as well as changing of backgrounds- If you create a  unique level from the assets that will. 

Changed scoring in levels 2 and 3- Changing scores in the inspector would not constitute as a significant change. Changing enemy behavior would constitute as a significant change.