For infinate 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 e:\cpc2.dat cheater.cht
debug e:\cheater.cht
e 1218 90 90 90 90
w
q
For the [EGA] version of this game, type:
ren e:\cpc1.dat cheater.cht
debug e:\cheater.cht
e 11e1 90 90 90 90
w
q
Then rename CHEATER.CHT back to its previous name.