For almost all the missions that didn't require a specific type of ship I used a doughnut ship consisting of 28 'basic' gummi blocks (don't remember the name, but they're all the same with different shape), 16 neon bars, 2 gravigas and 2 blizzagas. I made whatever adjustments I needed in order to pass the requisites of EX missions and It was much easier than I thought. The most difficult mission was one of the Pirate ship levels, because I had to stick to a blueprint type (highwind, I think) and it was hard to avoid the cannons and reach the score. And one of the broken highway missions, because there was a tricky enemy that I missed many times until I finally got its treasure.