Unlimited lives
You need to hold the Right Mouse Button when the screen blanks as the game is loading.

Hex Cheat
For infinite lives in the game, use the DOS utility DEBUG. First backup your game to be changed, then type the following from the DOS prompt:

ren baal.exe cheater.cht
debug
a 100
mov dx,es
add dx,1000
mov es,dx

g 108
r ip
100
n cheater.cht
l
e es:2251 90 90 90 90
Then type:
w
q

Then rename CHEATER.CHT back to its previous name.