Control button? Don't you mean the shift-button?
The control button is used to assign troops to groups.
Shift allows you to select more.
I found a problem when my younger brother was playing. In the second or third tutorial (the one where you make the raid fleet), he tried to send a normal fleet to tatooine and was unable to do anything else except press the begin battle button. Because he could not go back, or play that space battle, the only way to get anywhere was by ctrl-alt-delete.
Don't know if this problem has been fixed yet, but I thought I should mention it just in case.