In the final stage, the final boss's aim can be controlled by using the shoulder buttons.
Hard Mode
To toggle hard mode, input the following code on the title screen: Up, up, up, down, down, down, down, down, right, right, left, X, Y. If done correctly, the red and blue parts of the title screen will inverse, and the witch and hero will switch places. You have three new files to play hard mode on. Typing in the code again will allow you to go back to selecting the files for normal mode.
Time Trial and Survival Modes
To unlock Time Trial and Survival Modes, first clear the game. After defeating the final boss, select the file that you've beaten the game on and highlight Stage 7 (Coastal Battle) on the world map. Pressing up or down on this stage will allow you to play these special modes.
Unlockable
How to unlock
Survival Mode
Clear the game, then press "up" from Stage 7 on the map.
Time Trial Mode
Clear the game, then press "down" from Stage 7 on the map.