Free Ship - Shortly after you reach the first set of spinning walls, you'll reach a lake. If you dump bombs into the lake, a flag with an ''S'' on it will appear. Flying over the flag will give you a free ship.

Skip the Fortress - Just before you get to the Fortress part of the game, press pause. Unpause the game right after that, but instead of having to fight the Fortress, you'll be able to just move right past.