This game will be single player.

"About COOP: It won't be there in this games campaign, as it doesn't make sense. But i was always thinking about a coop game set on the same island, but that would be a future project"

Link https://gtm.steamproxy.vip/app/1645630/discussions/0/3109152828484851782/#c3109152828486962351

Read their discord. In project chat. Link
https://discord.gg/USVbFM5B4k