Solo play
Big Walk is designed around communication between at least two people. The official player range begins at two, so this is not a conventional solo campaign.
Local co-op
The official product information describes online co-op. It does not list split-screen or same-device local multiplayer; do not buy it expecting couch co-op without a new official announcement.
Matchmaking
There is no public matchmaking. You need to arrange a group yourself, then use the game’s private session flow. Community Discord servers can help find players, but none should be presented as official unless House House links it.
