C28D-7D0F Infinite ammo
C228-E7D4 Infinite lives
DF25-84D4 Start with 1 life
D125-84D4 Start with 6 lives
DB25-84D4 Start with 9 lives
C2CC-5D64 Infinite energy
71729-8704 + 1728-74D4 Start with more ammo
622C-7764 Start with chain gun
622C-74A4 Start with machine gun

The rest of the codes take effect only after losing your first life
622A-7DD4 + D02C-7DA4 Start with special weapon 1 (super machine gun) and ammo
6228-7704 + D92C-7DAF Start with special weapon 2 (rocket launcher) and ammo
C289-77DF Infinite ammo for special weapon 1
C28F-84DF Infinite ammo for special weapon 2