(This is version specific - backup first!!!)
For immortality, unlimited bullets & bombs: hex edit bmenace1.exe
Offset 61-64 change 2B 46 08 to 90 90 90
Offset 254-257 change FF 0E 08 44 to 90 90 90 90
Offset 117-120 change FE 0E 0D 44 to 90 90 90 90
Offset 468-471 change FE 0E ED 43 to 90 90 90 90