GamePart_Title has TWO nested state fields.

OUTER -- sub_821C7850, the part's dispatcher
  821c786c  lwz    r11, 16(r30)      ; only runs when this+16 == 3
  821c7870  cmpwi  cr6, r11, 3
  821c7874  bne    cr6, <exit>
  821c787c  lwz    r11, 132(r30)     ; phase = this+0x84
  821c7880  cmplwi cr6, r11, 0x4     ; five phases, 0..4
  821c7888  lis/addi r12, 0x821C78A0 ; jump table
  821c789c  bctr

    phase 0 -> sub_821C5690   (the splash -- independently identified as the
                               splash mechanics in the iterate3E notes)
    phase 1 -> inline block at 0x821c790c
    phase 2 -> sub_821C5818
    phase 3 -> sub_821C5EC0
    phase 4 -> sub_821C6458   (the title/menu machine, below)

  All four call sites forward the SAME three arguments: (this, r29, r28),
  where r28 is this function's own third argument -- an EVENT CODE passed
  through unchanged from ITS caller.

INNER -- sub_821C6458, the title/menu machine (phase 4 only)

DISPATCH
  821c6474  lwz    r11, 136(r30)     ; state = this+0x88
  821c6478  cmplwi cr6, r11, 0x9     ; 10 states, 0..9
  821c647c  bgt    cr6, 0x821C75B8   ; out of range -> default
  821c6480  lis    r12, 0x821C
  821c6484  addi   r12, r12, 25752   ; jump table at 0x821C6498
  821c6488  slwi   r0, r11, 2
  821c648c  lwzx   r0, r12, r0
  821c6490  mtctr  r0
  821c6494  bctr

NOTE: a disassembler decodes 0x821C6498..0x821C64BC as `lwz r16, N(r28)`
instructions. They are the jump TABLE's ten words, not code.

STATES
  case 0  -> 0x821c64c0   installs "TITLE_SCREEN"
  case 1  -> 0x821c65d0
  case 2  -> 0x821c66e4   installs "TITLE_MENU"
  case 3  -> 0x821c6b18
  case 4  -> 0x821c6b5c   nested switch, table at 0x821c6b7c (live: 0,3,5,8)
  case 5  -> 0x821c6fd4
  case 6  -> 0x821c7028
  case 7  -> 0x821c72dc
  case 8  -> 0x821c733c   installs "LOADING"
  case 9  -> 0x821c7558

TRANSITIONS -- every `li rX,N ; stw rX,136(r30)` in the function
  from  to    at
    0    1    0x821c6598
    0    2    0x821c65c8
    1    2    0x821c66a4
    1    2    0x821c66dc
    2    4    0x821c6afc
    3    4    0x821c6b54
    4    0    0x821c6e00
    4    5    0x821c6e70
    4    8    0x821c6ed0
    4    8    0x821c6f20
    4    8    0x821c6f7c
    4    8    0x821c6fcc
    5    6    0x821c7020
    6    7    0x821c725c
    6    9    0x821c72a8
    6    2    0x821c72d4
    7    9    0x821c7334
    8    2    0x821c7548
  (state 9 stores nothing -- terminal within this function)

THE CONDITION ON STATE 4's EDGES -- decoded
  sub_821C6458(this, ?, r5) takes an EVENT CODE in its third argument.
  State 4 -- the input-waiting state -- dispatches on it:

    821c6b5c  cmplwi cr6, r27, 0x19     ; 26 events, 0..25
    821c6b60  bgt    cr6, <default>
    821c6b68  addi   r12, r12, 27516    ; table at 0x821c6b7c
    821c6b78  bctr

  Only 6 of the 26 are handled; the other 20 fall through with no state change.

    event  0 -> block 0x821c6be4 -> state 0   (TITLE_SCREEN -- back to the title)
    event  3 -> block 0x821c6e78 -> state 8   (LOADING)
    event  5 -> block 0x821c6f84 -> state 8   (LOADING)
    event  8 -> block 0x821c6f34 -> state 8   (LOADING)
    event 10 -> block 0x821c6e28 -> state 5
    event 25 -> block 0x821c6ed8 -> state 8   (LOADING)

WHAT IS NOT DECODED
  * what the event NUMBERS mean -- they are forwarded unchanged from
    sub_821C7850's caller, so the vocabulary is defined at least one level up -- button id, menu-item id or message id;
  * the conditions on edges out of states other than 4;
  * what states 1, 3, 5, 6, 7 and 9 do (they install no named screen);
  * state 3 is never a destination here, so something outside this function
    sets it.