What do the official listings show?
Steam labels Big Walk as Online Co-op and Cross-Platform Multiplayer. Nintendo lists the cooperative player count under online play. Neither reviewed page presents a split-screen mode.
How should a same-room group prepare?
Use separate supported devices, accounts, game access and internet connections. You can still sit in the same room, but the game session itself should be planned as online play unless an official update explicitly adds local co-op.
Frequently asked questions
Can two players share one screen in Big Walk?
No reviewed official source advertises that feature. The supported cooperative mode is described as online.
Why is this page marked partial?
The official listings clearly advertise online play, but the reviewed FAQ does not contain a direct sentence saying that split-screen is impossible.