Unlimited time:
Load or reset the game, then execute the following BASIC command before running or restarting the program. 

POKE 15537,165 
No bombs:
Load or reset the game, then execute the following BASIC command before running or restarting the program. 

POKE 19019,0 
Invincibility:
Load or reset the game, then execute the following BASIC command before running or restarting the program. 

POKE 17427,0