Cheat mode:
Load or reset the game, then execute the following BASIC commands before running or restarting the program. 

POKE 1007,55
POKE 1011,132
POKE 1012,255
SYS 6912 
Invincibility:
Load or reset the game, then execute the following BASIC commands before running or restarting the program. 

POKE 2460,255
POKE 2465,255 
Unlimited lives:
Load or reset the game, then execute the following BASIC command before running or restarting the program. 

POKE 3060,173 
100 lives:
Load or reset the game, then execute the following BASIC command before running or restarting the program. 

POKE 2311,100 
100 Strata Bombs:
Load or reset the game, then execute the following BASIC command before running or restarting the program. 

POKE 2316,100 
Faster attack rate:
Load or reset the game, then execute the following BASIC command before running or restarting the program. 

POKE 8575,0 
More enemy bomb firing:
Load or reset the game, then execute the following BASIC command before running or restarting the program. 

POKE 13151,7 
Increased gravity:
Load or reset the game, then execute the following BASIC commands before running or restarting the program. 

POKE 5901,192
POKE 5930,128
POKE 5947,2