There’s now multiplayer in the PC version of Ys IX: Monstrum Nox, as NIS America announced local co-op is here. People who download the free 1.1.2 patch can begin playing with others. The second player is treated exactly the same as the first one. This means they can do everything the first player can do, like switch characters or find landmarks. However, the feature is referred to as “experimental,” which means people could experience issues.
To start Ys IX multiplayer, you need to play for a bit and then enable co-op in the settings. Once it is set up, people can use two controllers to play together. (The announcement specifically mentioned controllers and not keyboards.) Once a second player is around, the two can explore and fight together. As mentioned before, the second player can do things like trigger events or open chests like player one. The only thing player can’t do is use the map or menu.
As for the experimental element, NIS America brought up two side effects of this. One is that the game could softlock one of the two people out of something if players aren’t careful. The other is that both characters control the camera.
Here’s a video showing how co-op multiplayer works in Ys IX on PCs.
Ys IX: Monstrum Nox is available on the Nintendo Switch, PlayStation 4, PC, and Google Stadia. PC patch 1.1.2 is live.