This portion of the Luigi’s Mansion 3 guide explains how to unlock Gooigi so you can play 2 player co-op.
Source: IGN.com How to Play Luigi's Mansion 3 Co-Op and Unlock Gooigi
This portion of the Luigi’s Mansion 3 guide explains how to unlock Gooigi so you can play 2 player co-op.
Source: IGN.com How to Play Luigi's Mansion 3 Co-Op and Unlock Gooigi