What the official channels actually say
Co-op multiplayer is confirmed across PC, PlayStation 5, Xbox Series X|S, and mobile: you team up for fantasy action quests across Idyll and for alpha boss battles — the massive encounters that headline the multiplayer pitch. Defeating them feeds resources and experience back into your roster.
Because Twine changes how each player traverses and acts, group play is where party composition gets interesting: four players twined with four different Aniimos are effectively four different movement kits. That is the theory, at least — the practice starts September 16.
A reasonable way to prepare
Keep a diverse roster early. The official site's framing — explore everywhere, discover new Aniimos as part of the continent's loop — implies traversal variety matters more than a single maxed creature. For alpha bosses specifically, coordinating which Aniimos your team brings will likely matter more than levels.
We will follow up with launch-week impressions of the co-op loop once servers are live.