There appears to be some strange functions left in the
games code. Most of them are only visual. What these were for, I have no real idea.
Debug feature 1
XX is 00 by default
01: Disables some parts of certain character models(easily noticeable on Conker, his top eye textures is invisible, allowing you to see the rest of the eye region.(Tested only on Project 64. Results on other emulators or on real hardware may vary))
04: Texture strecthing disabled on most models.
05: value 01 - 04, combined
Debug feature 2
XX is 00 by default
04: Basic character shadows disabled. A few 2D sprites also seem to be affected.
Debug feature 3
XX is 20 by default
24: Texture details in Background box is now displayed as differently coloured square tiles.
40 to 70: Rooms(not counting outside areas) become darker.
Crash Debugger Values:
This only exist in the PAL version of the game. if set to 01 or higher, the crash debugger will be entered. Setting it back to 00 and picking retry code will resume the game.
Unknown. Doesn't seem to do anything in the retail game. Also only exists in PAL, like the above value.
this address is always set to zero by the game, no matter if an GS code forces it to be 01 or some other value. What this one is about, I can't really tell.
Level Appearance Scaling:
No idea what this were used for. Possibly to test appearance of levels in the game to see how they looked like when stretched at insane dimensions? Doesn't seem to be utilized by the game in any way.
Beyond the Screen Display:
Rather neat, strange, may even trigger epileptic seizures, but also a bit interesting. This normally cannot be seen, but underneath the screen display is an framebuffer of some kind, which shows the frame that were previously drawn at the top side for about a few milliseconds before being updated with a new frame, which goes on like this. Basically, the top area is constantly updated, with the bottom area showing the previous frame. This will not work on emulators however, because the bottom part is never emulated properly, leaving it showing only some artifacts, or just black space.