Kingdom Hearts II/Gummi Ship

Most of the time, when you're traveling to a new world from a world you just played though, you have to play through a Gummi Ship Route. For example, after you clear Hollow Bastion, you unlock the Land of Dragons and Beast's Castle, but in order to access either of the worlds, you have to play though the Gummi Ship Route. In some cases, like the route between Disney Castle and Hollow Bastion, you do not have to play a Gummi Ship level to access it (though is very rare and not the case for most paths between worlds). There are a total of nine Gummi Ship Routes in the game, each with three bonus missions. Clear at least the second missions for every world to collect all blueprints (though for Assault of the Dreadnought, you'll have to clear all three).

Building the Donut
In order to make Gummi Ship missions much easier to complete, construction of the Donut ship is essential. Begin by building a square in the Gummi Ship editor; simply place one layer of blocks around the grid, so that the center is empty. This will cause all enemy bullets to pass right through the ship, dealing no damage (although there are a few attacks that are exceptions, it is otherwise the perfect machine). Next, attach cannons to the center of the bottom and top sides, as well as the left and right. Lastly, attach whatever neon items you have (these should be under the "Auxiliary" category of the weapons menu) in order to increase the ship's max HP.

Gummi Ship Routes

 * Asteroid Sweep: Hollow Bastion to The Land of Dragons
 * Stardust Sweep: Hollow Bastion to Beast's Castle
 * Phantom Storm: The Land of the Dragons or Beast's Castle to Olympus Coliseum
 * Floating Island: Disney Castle to Port Royal
 * Splash Island: Disney Castle to Atlantica
 * Ancient Highway: Port Royal to Agrabah
 * Broken Highway: Port Royal to Halloween Town
 * Sunlight Storm: Agrabah or Halloween Town to Pride Lands
 * Assault of the Dreadnought: Radiant Gardens to the final visit of Twilight Town