I was playing the game more time and I got noticied what the alien saucer dont appear in a lot of waves what can join.
For this i listed the waves what can appear
-Bubble bath (Only Central Enemy)
-Chick in the armor
-Eggshell Fields
-Egg cyclone
-Spawning Trouble
-Divide And Conquer
-Tegnology Advanced
-The Yolk-StarTM
-Look in all Directions
-Chicken Terminators
If add restictions will appear in:
-Chicken Quadrants
-First Impresions
-The Next Generation
What think?