What about something that notifies you when you're being spied ?
Or, more precisely, a system of percentage of chance to be notified when people spy you ?
There would be a building for this :
level 1 : 10 % chance to be notified of a spy
level 2 : 15% chance " " "
A second possibility is to instore a system of percentage of chance to spy somebody without being spotted, I mean a percentage of chance not to notify the guy you spy that you spied him.
There would be a building such as :
lvl 1 : 10% chance to spy without notifying
lvl 2 : 15% chance """
The first option would imply that at a low level (of star base), people will be able to spy you without being spotted, but at a high level, you will be able to know nearly every time you are spied. The second option implies the contrary.
That would make the system of attack more exciting, and add more strategy : you don't want the guy you are about to attack to use his "Lightning Bullet" (which improves his turrets' attack), because he just saw that you spied him !
So maybe sometimes it is better to attack him without spying him just before !
Tell me what you think about it