Hackers have discovered that the entire arcade version of F-Zero AX was included on the Gamecube F-Zero GX disc. They've provided an Action Replay code that starts the game in arcade mode.

http://www.nintendolife.com/news/2013/0 ... _f_zero_gx

Here's a c/p of the Action Replay codes in case the article ever vanishes from that site:

If you're using a PAL copy of the game, you'll need to enter the following code:
Z60V-MZG0-VRAQ2
3DFJ-55T9-J5J7P
NBCW-U1NV-0JDJG
HK7K-0RFW-FNQ8Y
PF4U-P5D0-862X1
9D4X-PVXV-R3FNV
Q7PM-1678-XE7FW
UAB4-HZ2F-AW6X5
T6UV-03PE-1H26C
BN71-WCD5-DYDNW
FHW5-F3D3-B2UZ5
NJR5-FE19-GQ851
5FRQ-P6M4-096F3
85KV-QPJD-4U999
VXM8-U9Y8-URZPR
VZFH-H43M-5N6E3
G71V-JPGY-BPDDZ
GUZD-V5KT-UBKA8

And for those with NTSC copies, this shorter code will do the job:-
61TA-AXPK-UAV9E
EHJV-6U30-2DTVE
NBCW-U1NV-0JDJG
HK7K-0RFW-FNQ8Y
PF4U-P5D0-862X1
7HUZ-2PJY-J5TTU
Q7PM-1678-XE7FW
YW2J-AUVE-R79V8
T6UV-03PE-1H26C
R91R-1A6J-ZXN30
1GHM-VQ7W-7HBWW