Does the VC version of Starfox 64 not have multiplayer? Is it unlockable?

Are you using a combination of GameCube/Classic Controllers by anychance?

If so, GameCube controller needs to be plugged into the port of the player they want to play as.

This is assuming the multiplayer in SF64 is still intact, which I'd be starstruck if not.

when did you download it??

if you did a while ago there was some update you can get for free by redownloading it, maybe that adds the multiplayer