how would you like to --- MAKE YOUR OWN CODES?!?

the password basically works like this:

the first four digits determine the stage and the strength of your plane, and
the fifth digit is the checksum.

digit 1 does the stage you're on,
digit 2 does your total offense and defense (from 1 to 6),
digit 3 does both the energy level of the plane and the power of your special
        weapon (from 1 to 6),
digit 4 does the time limit of your special weapon (1 to 6).
follow the tables below to get these letters set up.

now, let's calculate digit 5. add the numbers you gave for offensive power,
defensive power, energy level, special weapon strength and special weapon
time limit. now look at the table for digit 5 below. if the stage number you
chose is less than the minimum stage number on the key, then the code won't
work. if the stage number you want is equal to or greater than the stage
number on the key, use the code digit below it on the key to complete the
code.

as an example, let's say we want everything possible.

we want to start at the last stage, so our first digit will be T.

we want maximum offense/defense, so we'll set digit 2 to Y (offense is 6, and
defense is 6).

we'd like maximum special weapon/energy and plane energy, but let's just set
weapon energy to 5 for this (as you can see from the table, the maximum total
number of points we can have is 29, so we can't max out everything.) so, our
3rd digit is 1.

we'd like a biiig time limit, so digit 4 will be 9.

now for the checksum. 6 plus 6 plus 5 plus 6 plus 6 equals 29, and the stage
we've chosen is high enough for that, so we'll use U for digit 5.

this gives us TY19U. :)

DIGIT 1
stage 1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
code  0  7  E  L  S  Z  I  P  W  3  A  H  U  5  K  F  1  6  8  D  M  R  T

DIGIT 2
            offense
          1 2 3 4 5 6
          -----------
        1|3 2 1 0 4 6
defense 2|A 9 8 7 B *
        3|H G F E C D
        4|I N M L J K
        5|P O T S Q R
        6|W V U Z X Y

DIGIT 3

          energy
          1 2 3 4 5 6
          -----------
        1|I O V U W H
energy  2|D J Q P X C
        3|8 E L K R 6
        4|3 9 G F S 7
        5|Y 4 B A M 1
        6|T Z 0 5 N 2

DIGIT 4
time limit 1 2 3 4 5 6
      code 1 6 0 W N 9

DIGIT 5

Pts.    8  9  10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29
Minimum 1  3  4  5  6  7  7  8  9  10 11 11 12 13 14 15 16 17 17 18 20 22
stage
Code    1  3  A  N  X  P  D  8  G  S  Q  J  E  F  M  R  K  L  Z  O  5  U