Crossplay

Is Natsu-Mon: 20th Century Summer Kid crossplay?

Crossplay does not apply to Natsu-Mon: 20th Century Summer Kid: it has no online multiplayer.

Natsu-Mon! 20-seiki no Natsu-yasumi is an adventure game where you spend a summer as a boy. Catch insects, fish, swim in the sea, and interact with the towns people. You can also travel to neighboring towns by train and participate in festivals at night. By experiencing various things, the things you can do and the places you can go will expand.