All TR 1 cheats (the backwards stuff) works also in TR 2, only with
 the difference that you have to light a torch.

HexCheats:

 Load the savegame into a hex editor and change the following
 offsets:

 For all weapons (without ammo), 255 medi packs and 255 torches

 00000080: 00 0C 00 00 00 00 00 00 - 00 FF FF FF FF FF FF FF

 (file offset 137-143)

 For the # of the saved games

 00000040: 00 00 00 00 FF FF FF FF - 01 00 00 01 00 00 00 00

 (fiole offset 75)

 Edit the the ammo after Venice

 Change the following offsets to 40 54 89:

 4760, 4764, 4768, 4772, 4776, 4780

 In the Demo:

 Do you want to have all weapons into Lara's demo?
 To hack TR2 you must open your savegame0.dat file (save it at the
 beginning) and change these lines:

 080   000C FFFF FFFF FFFF FFFF FFFF FFFF FFFF
 FC0   E803 0000 0AFF 0000 0BFF 0000 0CFF 0000
 FD0   01FF 0000 0DFF 0000 0EFF 0000 0FFF 0000

Hint:

 The less you save during the game the more you can from Lara in
 the shower at the end of the game.