Castaway Diary: Portal to the Unknown Isles
Castaway Diary: Portal to the Unknown Isles: co-op, on PC.
What the developers promise
Not out yetPlayers can explore the island solo or team up with others. Friends can build houses together, take on challenging dungeons, and share the adventure as a team.
An AI summary of the Steam page from November 2026, not from players, and it may still change. What players say shows up here once the game is out.
Want to play Castaway Diary: Portal to the Unknown Isles with friends?
Pick a night together in Lobbli: everyone marks when they are free, and you see which evening works.
Quick answers
Is Castaway Diary: Portal to the Unknown Isles co-op?
Yes, Castaway Diary: Portal to the Unknown Isles has a co-op mode.
How many players?
The catalogue does not list a player count yet.
Split screen?
No split screen mode is listed for it.
Which platforms?
PC.
Can you play it online?
Yes, according to its Steam page.
What kind of game is it?
RPG, Adventure, Indie
Who makes it?
REMIMORY
From its Steam page: co-op, online play.
About Castaway Diary: Portal to the Unknown Isles
Castaway Diary is a bright and charming anime-style survival adventure. Are you ready to escape to a relaxing island life with a group of lovely girls?