Eternal Darkness

(M) (Datel)
UYQC-N1UJ-UUF1W
F17E-P4TU-QTW4X
T0PC-ER7R-K0VR2
0TJC-ER2C-4963Q
0PGJ-Q9AW-CWA7G
ZZ3E-EZ0J-N6XBE
QF32-TVKT-KQ3DA

One Hit Kills (donny2112)
JZY3-0K40-F16U4
4Y1T-EQ2Y-26ADW

3 Insanity Pictures (donny2112)
0N19-YB29-YWP8B
R5XA-8YC8-G8Q6F
7J7Y-KVVZ-BRUDP

Infinite Ammo/Running (donny2112)
8NB5-HXZ2-0FTFH
UYK8-GVJ2-E0DPH

"That's not right" On/Off (Z+X/Y) (donny2112)
P1GU-W7NH-6TEQD
H822-4F5W-QA6ZF
UT4H-U71D-CR08A
M50B-XGDN-P7PZ5
ZZCB-8XHU-HCR08

Freaky Giant On/Off (L+D-pad Up/Down) (donny2112)
4U7R-0H8C-3ZG84
AT84-NJ2E-N9B72
3QRG-UE3C-CYKFA
07YP-GZN2-QMTHB
EUNR-8YJD-WKZWT

Run Fast On/Off(L+D-pad Left/Right) (donny2112)
UJRD-6H0U-2VRT8
UCF2-8NFJ-4P0QM
D60P-GK22-T1F5C
MTA7-ZDJN-20HX6
C241-XZU3-P2HA8

Zoom 2x/4x/1x (R+D-pad Up/Left/Down) (donny2112)
6QXA-B6V0-BDF2C
TF4Q-PV2D-92QDP
2HMY-JK71-G8W1J
MD74-UH3R-FWT7P
8DVW-N83A-ENHJZ
7QAA-94MD-UN750
8CDM-XRB1-6X77R

Unlock All Extras (donny2112)
VANP-9JZ7-9673T
PDM1-4N67-3FEWR
PR8G-WPY8-TNVBT

Extra "Jump to Game" Levels (Press L) (donny2112)
498Q-962Z-E8PV1
M975-5YM6-5E08T
6XT8-P7QM-M73RT
T38Q-X2EJ-MEN69

Notes

This will allow you to kill almost anyone with one head shot or just quicker than normal otherwise, but it affects you too. It will cause you to limp like you are low on health.

Turn on infinite health or Eternal Mode to keep you from dying in one hit.

I think they are three insanity pictures from in the game, but it is hard to tell. Pressing A or Start freezes the game, and there is no way out of it.