1-Player only.
Go into options and set them as follows:
Lives per game = 3
Bonus life = 25,000
Difficulty level = 5

1-Player only.
Go into options and set them as follows:
Lives per game = 5
Bonus life = 20,000
Difficulty level = 5
Play 'Yellow' version = No

1-Player only.
Go into options and set them as follows:
Lives per game = 3
Bonus life = 10,000
Difficulty level = 3
'Invisio' time per ship = 10
Men needed to warp = 4
Last warp allowed on wave = 10

1-Player only.
Go into options and set them as follows:
Lives per game = 3
Bonus life = 10,000
Initial Difficulty level = 5
Maximum Difficulty level = 15
Waves per planet = 5

1-Player only.
Go into options and set them as follows:
Lives per game = 3
Bonus life = 25,000
Difficulty level = 5

1-Player only.
Go into options and set them as follows:
Lives per game = 3
Bonus life = 30,000
Additional Bonus life = 30,000
Difficulty level = 5
Continuous fire = On
Sideways mode = Off