It's possible to trigger one of three error messages at the title screen if you have attached a Nintendo 64 Disk Drive (N64DD), suggesting that an expansion disk for the game was planned at one point.

The three messages which can appear are:
*Error: 41 DEVICE_COMMUNICATION_FAILURE N64 Disk Drive or N64 Control Deck may not be connected properly.
*Error: 43 POWERONRESET_DEVICERESET_OCCURED N64 Disk Drive may have broken down.
*Error: 44 RAMPACK_NOT_CONNECTED Jumper Pack may be left in N64 Control Deck.