30 FOR L%=0TO2 STEP2
40 P%=&C00
50 [
60 OPT L%
70 JSR &FFF4
80 LDA #&60:STA &1A1D:STA &1A2A
90 STA &2845 \ SOME IMMORTALITY
100 LDA #&EA:STA &24F5:STA &24F6
110 STA &2887:STA&2888 \ INF LIVES
120 RTS
130 ]:NEXT
140 *LOAD OMCL
150 ?&BAA=0:?&BAB=&C:CALL&B00

Lines 80 90 and 100 give immortality except for falls. Remove line 90 as the game probably plays better without it. Line 110 gives infinite lives. This on it's own is probably sufficient.