Successfully complete House Of The Dead 3, then go to House Of The Dead 2. You will take an elevator down to House of The Dead 2. On the way down, the door will open a couple of times. Shoot all the enemies as quickly and as accurately as possible to get items for original mode in House Of The Dead 2. Complete House Of The Dead 3 again to repeat the process. Every time you do this, you will get new items for original mode. This works best if you have unlocked the free play option for House Of The Dead 3.