Well, I'm not sure you would lose, because I usually need to retry most campaign mode mission about three or more times. But, despite the six star difficulty of Sinking Feeling, I beat it with only one or two retries. I know I'm getting better, but I tend to move without too much thought of the enemies position compared to mine. That's why cannons and minicannons are such pains for me. I am good, but there's probably a lot of people who can beat me. I'm probably above the average player, but, if so, not by much. I'm...well, you get the point.