Press [Ctrl] + [Alt] + [Shift]
+ D during game play and watch your money increase. Repeat
to get more money. Note: Do not do this too many times or you
will end up with a negative amount.
Also, this changes the "Help" button to "Debug".
In debug mode, there are some interesting things. You can go up
or down a grade (all the way up to five star).
Strategy guides from GameFAQs