Complete any act 1 (completing the game with an more advanced version of the above code will unlock the Options) and press C. It will reverse gameplay to when the code was entered and will play the "Survivial!" sound. Enter in the code you first tried and press D 15 times (the demo won't play when you enter the code) and press enter.
Unlock "levose" (level select) by pressing D, D, D, Down, Right, Left, Up, Right, Left on the keyboard . Then start the game.
This game is just an check for the trilogy so there is no number skips, so there is no level select. This is why the game is underrated also.
This is when Ryau became as good as the first game, because Ryau 2 was effortless. At least the title screen doesn't have the monster form of Fins like Ryau II. Big upgrade. Go to listen, press 25678 on the keyboard. Quickly press up until you see the word "SETTINGS V2.5" and press it. The code will be transfered to the "LISTEN V2".