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:

For the CGA version of this game, type:
ren cpc2.dat cheater.cht
debug cheater.cht
e 1218 90 90 90 90
Then type:
w
q

For the EGA version of this game, type:
ren cpc1.dat cheater.cht
debug cheater.cht
e 11e1 90 90 90 90
Then type:
w
q

Then rename CHEATER.CHT back to its previous name.