Too easy to quit the game. I was working on an elaborate ship in the VAB the other day, and instead of the launch button, I hit the exit button by mistake. By reflex I hit escape, but that took me to the "Start Game" menu, where I clicked Back, thinking it would take me back to my game instead of starting a new one. But that just brought me to another menu, and I just wanted it to quit putting up menus, so I clicked Quit. It asked me if I wanted it to "Really Quit", and of course I did, because I was getting frustrated by this point, and I clicked Yes, really!, and it quit out of KSP completely. I really think there should be one or ideally two more confirmation dialogs so that the player will understand that the game is about to be closed, because as it is now, it's waaaay too easy to exit unexpectedly.