Spying is boring.
At this point in time it's not an interesting game mechanic at all. You pay x credits and get y amount of information in z amount of time.
There's no spice to it whatsoever. You might as well replace it with a button that takes 500 credits and gives you all the information. Or you could even make it automatic, since there are few situations where you wouldn't want to spy, if the game is long enough.
Basically in a long enough game everyone knows everything about everybody and there's no way to stop it.
It needs to be drasticly expanded to start being fun. There should be ways to prevent your empire from being spied upon. There should be ways of feeding bad information to empires that are spying on you. And lastly, getting caught in high-level espionage should be considered an act of war.
