Infinite Lives
POKE 9065,00
POKE 5B8F,C9
This poke removes the DEC A from the following code block:
9062 LD A,(ActivePlayer_Lives)
9065 DEC A
9066 LD (ActivePlayer_Lives),A
Infinite Fuel
POKE 8DAC,00
POKE 8DAD,00
This change just removes the code which handles subtracting the expended fuel.
SBC HL,BC
Becomes;
NOP
NOP
Immunity
POKE B2D0,C3
POKE B2D5,A7
Infinite Time
POKE ABDD,18
This changes the command;
JR Z,ABE5
To instead;
JR ABE5
No Enemies
POKE 946F,C9
This changes the command;
RET NZ
To instead;
RET
This section does a couple of checks. The one this poke changes, essentially keeps the game in a "pre-game" state - so the GameDelayTimer check always returns as if the game hasn't yet properly begun.
Destroy Missile With One Shot
POKE AF6A,18
This changes the command;
JR Z,AFB1
To instead;
JR AFB1
Which is the check to see that the shots counter (IX+16) is zero. Instead this jumps to AFB1 when the code is reached (so jumps with any value).