Cheats:

Trial mode:
     Press  Up,  Down,  Down,  Right,  Right, Right, Left, Left, Left,
Left,  C-Down + Start at the main menu to unlock trial mode. This mode
allows any level in the game to be played

Get Any Level:
     At the main menu press Up, Down, Down, Right, Right, Right, Left,
Left, Left, Left, C-Down + Start.

All M. Characters:
     At the main menu press Up, Down, Down, Right, Right, Right, Left,
Left, Left, Left, C-UP+ Start.

Unlimited Pistol Ammo:
     To  get  unlimited  pistol  ammo  press  "b"  when you are out of
bullets on the story mode on easy, normal, or hard setting.

Get Sudden Death, Trial and Max Power:
     Finish the game with the hard difficulty setting.

Unlimited Health:
     At  the  main  menu press Down, Up, Up, Down, Down, Down, C-Left,
C-Up, C-Up, and start

Infinate Ammo:
     At  the main screen press C-Up, C-Up, C-Up, C-Up, C-Down, C-Down,
C-Down, C-Down, C-Down.

Defeat the Fire Boss:
     When  you  first  start out there are two men on boxes going back
and  forth and the boss is runnig right by a box, when he gets near to
it  shoot  the box and it will blow up and do alot of damage. Then get
rid of the two men on boxes after they are gone run( or roll)up to the
boss  (avoiding  his fire) and crouch right beside him. Once there you
can take as many shots as you want and the flames won't hit you.

Beating Deathmask:
     When fighting Deathmask it is best to turn to the right and shoot
that  guy.  Then  hide behind a computer screen and kill the minion on
the  left.  Then  go  to the wall that is to the right of you and hide
behind the outings. Then shoot at him until he comes out of his hiding
space,  then  shoot the explosive barrels behind him to take away half
of his live. That makes it much easier to do.

Beat Dan, last boss:
     Shoot  him  once at the beginning. Then he will run over in front
of  some  canisters. SHOOT THE CANISTERS. After a while he will run up
to  the  same  level as you. Shoot the canister that he stands behind.
Then  shoot  him  until  he  dies.  Watch out his grenades during this
level.