From the official forum (http://forum.exoplanetwar.com/viewtopic.php?f=9&t=142):
“I’m afraid there’s no such option as to delete an account on demand, at least not at the moment.
However, rest assured that all your account info is kept in strict confidence.
Therefore you don’t need to worry about anything even if you left your account inactive.”
We’ve heard nonsense like this before… We suggest you change all your personal info into rubbish for the time being and hope the delete option will once be implemented, and send complaints to email@example.com.