The GBA minigames from the original GameCube version are still found in the files, though the eggs are already visually and functionally replaced with the default one like retail.
Unlike retail, there's a file called GCAX.conf, which looks to be a config file for the AX sound library for GameCube hardware. A similar file can be seen here
;----------------------------------------------------------
; GCAX (AX SNDLIB) Configuration
;------------------------- ---------------------------------
; Format
;
; Anything after the semicolon will become a comment
; LF (Unix), CR (Macintosh), and CR+LF (MS-DOS) may all be used as newline characters.
; Do not write in Japanese except in comments
;
; Numeric Values
; 0 0
; 0[0-7]* Base 8
; 0x[0-9A-Fa-f]* Base 16
; $[0-9A-Fa-f]* Base 16
; [1-9][0-9] Base 10
;
; <s>
; White Space (space or tab)
;
;----------------------------------------------------------
;AramBank - Setting the ARAM Bank Size
;AramBank <s> Bank Number <s> Bank Size
;----------------------------------------------------------
;The ARAM bank's size is fixed during the program's runtime,
;but you can change its size at launch by setting it in this file.
;
;Note that only waveform data will be loaded into ARAM.
;
;------------------------------------------------- ---------
; ARAM Bank Size Settings (8M for Giant Egg)
;----------------------------------------------------------
AramBank 0 830000
AramBank 1 800000
AramBank 2 700000
AramBank 3 0
AramBank 4 970000
AramBank 5 0
AramBank 6 1460000
AramBank 7 570000
AramBank 8 860000
AramBank 9 860000
AramBank 10 860000
AramBank 11 0
AramBank 12 0
AramBank 13 0
;7620000
;------------- ---------------------------------------------
; Reverb Settings
;---------------------------------------------- ------------
ReverbHTime 1000 ;msec
ReverbHPreDelay 10 ;msec
ReverbHDamping 80 ;%
ReverbHColoration 50 ;%
ReverbHCrosstalk 30 ;%
ReverbHMix 100 ;%