If you own a non-USB PS2 driving wheel and a GunCon 2, plug the driving wheel into the first controller slot and plug the GunCon 2 in the first USB slot. You can now change the controller options to make the pedals of the steering wheel act as the reload button. The use of the pedals will mimic the actual arcade set-up.
Clear the Rescue Mission to unlock the Crisis Missions.
By simply dying in arcade and rescue modes (respectively), your continue credits increase by one each time. This will go into infinite credits after more than six failures.
Clear story mode on arcade settings achieving an accuracy of 75% or greater.
Clear the entire Rescue Mission with an accuracy of 75% or higher.
Beat the game at normal difficulty under 30' 00.00" (thirty minutes) to unlock unlimited ammo for all non-Handgun weapons. This figures into an average of 3'00.00" per stage - the more time you shave off at the end of each area, the better off you are.
Clear the entire Rescue Mission under 25' 00.00"
Play through the story mode on arcade or rescue settings without continuing to unlock Mirror Mode in Arcade Mode or Rescue Mode.
Clear the Rescue Missions for a new title screen.
Clear the game once to unlock the rescue missions.
Clear any stage in arcade mode to unlock its trial mode.
Complete all the crisis missions with gold medals.
First unlock unlimited special weapons ammo. Next select unlimited special weapons ammo. Then use only grenade launcher to clear either arcade mode or rescue mission.