Goto the options screen and enter the following:
L1 L2 R1 R2
A variety of "extra options" will now become available!

Piano Code:
After you've put the gold medallion in place on the clock tower the piano keys will be accessible.

There are seven white keys and five black keys. Below is the order in which they should be entered. In order to use the code below assume that the keys are numbered from left to right. For example, the first white key=1st the fifth black key=5th.
1 hit the 2nd white key
2 hit the 6th white key
3 hit the 5th black key
4 hit the 5th white key
5 hit the 1st black key

Beat the Door Puzzle Codes:
A,L,E,R,T

Beat the Zodiac Puzzle Code:
4,8,6

There are three different endings for the game there are three
different endings a good plus, a bad ending, and a bad ending plus. to get
them there are a lot of things to do.
for the good plus:While in the hospital collect the water bottle from the
kitchen.
-Go to the director's office and use the water bottle on the shattered vial
on the floor behind the director's desk.
-Collect the sample and continue until you get to the resort area.
-At the Resort area head to Annie's bar and save Kaufmann.
-Collect the thins that kaufmann dropped between the pool tables and head to
the indian runner
-Use the combo (0473) to open the lock on the back door of the store.
-Check the notes on the back wall behind the counter to find the access code
into the motel.
-Head over to the motel type the code from the indian runner 0886 into the
keypad.
-Go into the back room and collect the magnet.
-Go into the from office and unlock the main door.
-Head to Kaufmann's room (#3) and push the dresser over to reveal a hole in
the floor.
-Use the magnet on the hole to collect the motorcycle key.
-Go back into the back room of the motel and go to the garage.
-Use the motorcycle key on the motorcycle and meet with Kaufmann.
-Continue on with the game unil you get to the amusement park battle.
-Shoot Cybil until she drops her gun. Let her get close enough to grab you.
-when she's just about to grab you use the water bottle.
-finish the game.

When you do this you get a katana and a medallion as a prize