That's true. Luckily a lot of the later levels don't even have many Koopa's, let alone make it easy for you to fly through the whole thing. I'm having trouble remembering right now if you can even get him in the level you reach from Donut Plains. You might have to do the entire Star Road to get around to the right level, but I might be mistaken.
I thought someone might suggest that. I'm actually kind of tempted to tell you the truth. Hell, there are a lot of levels that are easier small.
Oh, and my skype is v1v122.