Here is some cool cheats.
Unlock all missions
8014af3c 0015
Have all weapons and items
8012a5bo ffff & 8012a5b2 ffff
all wepons and items 1:
85BB65B3CDCC
All Levels selectable:
85BD6F8BCEE2
all M-79 ammo all the time=3012A60E0063
allammo for Crossbow=3012A5FE0063
all ammo teargas gun=3012A62A0063
I hope..
infinite armor:
game shark d0089e680006 - 80089e6a2400