House of the Dead 2 cheats and cheat codes for Dreamcast

Ending Bonus room:
Finish the game in original mode without losing any civilians and 
reach minimum 1000,000 points

Unlock "Emperor" option:
Beat all Bosses in Boss mode

Unlock "Fight All" option:
Beat all Bosses in Boss mode

Unlock Goldman costume in the trunk of the car:
Finish the game in original mode. 

Change blood color:
Finish the game in Original mode.

Show score:
At the Title screen, press Left, Left, Right, Right, Right, Left,
Right, Start. You'll see a 0 score at the top of the screen to
confirm.

Infinite "one-hit kills" ammo:
Finish training mode and reach 5 red star rank on each stage. 

Free play in original mode:
Finish training mode and reach 5 red star rank on each stage.
After, finish boss mode and reach 5 red star rank. 
At last, obtain 2 stars in fight all mode.
The "Continue" option will change to "Free Play". 

Play as Gary instead of James
In single player mode use a controller in port B.

Training and boss modes:
Finish the game in Original mode.

Napalm Gun:
Get a perfect head shot on the first 3 zombies you see off in the
distance on the first stage. You'll see a gun on the ground if you
did it right. 

Bonus room A:
Get to the final boss and have saved all the civilians to access a
secret room with a bunch of good stuff. This room has 3 life ups, 2
diamonds, 2 gold frogs, 2 necklaces, 2 gold coins and a mushroom.

Bonus room B:
Get to the final boss (without saving all the hostages) with over
100,000 points to get an infinite credit powerup and a Rogan costume.

Bonus room C:
Get to the final boss (without saving all the hostages) with 70,000
-100,000 points to get a Dynamite Cop costume.
Submitted by Aston34