Unlockable Weapon 
Complete the following. 

Unlockable:      How to Unlock:
Unlimited Rifle  Get UFO Ending 

Unlockable Costumes 
Complete the following. 

Unlockable:      How to Unlock:
Savior           Finish the game once 
Butcher          Get the Bad ending 
Ambassador       Get the UFO ending 
Stalker          Use flashlight for less then 3 hours 
Collector        Collect more then 300 items 
Sprinter         Finish game in under 2 hours 
Sharpshooter     Kill 75%+ of all enemies with a firearm 
Weaponsmith      Kill 75%+ of all enemies with melee weapons 
Brawler          Kill 50%+ of all enemies with only your fists 
Cartographer     Looked at map less then 25 times 
Explorer         Distanced ran or walked greater then 22.5 km 
Daredevil        Finish the game without saving 
Fireman          Save Alessa in the beginning in less then 80 seconds 
Codebreaker      Do the Konami Code during your second playthough or up 

Unlockable Endings 
Complete the following. 

Unlockable:      How to Unlock:
UFO Ending       Use Room 502 Key at the Motel Room 
Bad Ending       Kill 200 enemies for second time 
Good Ending      Beat the game for first time