This looks interesting, but is the coop mode just shared screen couch coop, or is there more to it?

Haha, I literally wanted to ask the exact same question.

I saw on Co-optimus that it is "4 player" "local coop". But how does that work? Split Screen for 4 players seems a bit much.

Since I'm regularly holding a LAN party that option would be important. But from what I read it's not LAN either.

Based on the information I can find about it (which unfortunately hasn't included anyone actually recording themselves playing the co-op mode that I've found yet), it's not actually co-op. It's single-system splitscreen but it's a competitive game mode, not co-operative.

Problem with that being, of course, the prevalence of people (including GOG's official feature definitions) misusing "co-op" as "local multiplayer" and "multiplayer" as "online multiplayer only" for stupid reasons.

EDIT: Found an answer in Steam forums with a few people including one of the devs mentioning how it can work. Up to 3 players actually co-op - with players 2 and 3 taking control of companions who you have to find in-game first and recruit before the other players get to do anything.

https://steamcommunity.com/app/919360/discussions/0/3412055301118576585/