For every hour of playing your amount of continues will go up to a maximum of 9 continues/6 hours. After 7 hours, you'll have unlimited continues.
In one of the stages, where the blocks are everywhere, it's possibly to go right through the middle, instead of dodging to the side like you'd normally do.
In between the stable blocks, and the falling ones is a space small enough for your ship to fit in and stay there, thus avoiding all collisions with the blocks. It might take you several tried to get it in the right position.
While playing the game, press start and a pause menu will come up. Press and hold X and Y together to make the menu disappear.
Finish the game on normal difficulty without using a continue, or play for a total of 20 hours.
Complete the game on easy difficulty without using a continue or play for a total of 15 hours.
Gallery 1-Play the game for 5 hours or complete the Trial Mode without continuing
Gallery 2-Play the game for 10 hours or clear the game on any difficulty setting.
Game Mode Option-Play the game for 20 hours or beat the game on Normal without continuing.
Sound Test-Play the game for 15 hours or beat the game on Easy without continuing.