Please also note that all achievements in the game tied to the Game Center. We strongly recommend the use of a stable Internet connection to access your account. This gives you access to rankings, techniques and even new technologies. Gaining ranks will make missions more complicated but you can replay old missions by setting the difficulty at the time.
If you still do not want to connect to Google Play each time, there is an option in game settings to disable the automatic sign-in.
Sincerely, RedSun RTS Development Team
