If you pause the game and you should find that you are able to move your gun
target around.
For infinite lives in this game, use the DOS utility DEBUG. First backup your
game to be edited, then type the following from the DOS prompt:
ren gitum.frm cheater.cht
debug cheater.cht
e 3a6 c6 6 c0 85 c3 ff 2e 1f 0
Then type:
w
q
Then rename CHEATER.CHT back to its previous name.