Playing Worlds
Finding worlds
The Hub is Yumina's world browser. Three tabs at the top:
- Recommended -- trending and recommended worlds (default view)
- Following -- worlds from creators you follow
- Bundles -- asset packs for creators (you can ignore this)
Use the Filters button to sort by Recommended / Popular / Newest, filter by tags, and toggle sensitive content visibility.
Click any world card to see the full description, gallery, ratings, and reviews. Hit Start Playing to jump in.
Sessions
Every time you start a world, you create a session -- an independent save. You can have multiple sessions for the same world, each with its own story and state. The session picker shows your existing sessions with message count and last played time.
If a world supports multiple languages, language tabs appear at the top of the session picker.
The chat interface
Once you're in a session:
- AI messages are labeled as the narrator (or character names). Hover to see token count and model used.
- Your messages go in the input box at the bottom. Enter sends, Shift+Enter adds a new line. You can describe any action -- there are no fixed choices.
- Game panel appears on the right if the creator built a custom UI (health bars, inventories, maps, etc.).
Swiping (regenerating responses)
At the bottom of the last AI message you'll see a < 1/1 > control. Click > to generate a new response, < to go back to a previous version. You can generate several and pick your favorite.
Message actions
Hover over any message for action buttons:
| Action | What it does |
|---|---|
| Copy | Copy message text |
| Edit | Modify the message in place |
| Regenerate | Re-generate this AI message |
| Rewind | Delete everything after this message |
| Delete | Remove this message |
Input box extras
The + menu next to the input box:
- Continue -- have the AI keep writing without you saying anything
- Restart Chat -- clear all messages and start over
- Attach Image -- send an image to the AI
Top control bar
| Button | What it does |
|---|---|
| Undo | Undo the last exchange (your message + AI reply) |
| Export | Export chat as Markdown or JSON |
| Sessions | Switch between sessions |
| Branches | View and navigate the branch tree (see below) |
| Immersive mode | Full-screen, no UI chrome |
| Component panel | Show/hide the game panel |
Zoom
Magnifying glass in the bottom-left of the input area. Adjusts interface zoom from 20% to 200%.
Branching
Branching lets you explore "what if" paths without losing your current progress. You can branch from any point in a session, creating a new session that shares history up to that point but diverges from there.
The Branch button in the top bar opens a popover showing:
- Your current branch
- Parent branch (the branch you branched from)
- Sibling branches (other branches from the same parent)
- Child branches (branches you created from this one)
You can also branch from the latest message to create a quick "what if" fork.
Checkpoints
Checkpoints are save points you create manually. Use the bookmark icon next to the input box to:
- Save Checkpoint -- snapshot your current progress
- Load Checkpoint -- restore a previous snapshot
Use these before big decisions so you can always come back.
Multiplayer
Some worlds support multiplayer rooms. If a world supports it, you'll see a ROOM button in the library detail panel.
Creating a room:
- Click ROOM on a supported world
- Choose an AI trigger mode (when the AI responds)
- Share the invite link with friends
AI trigger modes:
- Manual -- host clicks a button to trigger AI response
- Timer -- AI responds after a set interval
- Round -- AI responds after everyone has sent a message
- Instant -- AI responds immediately to any message
Speech modes (host can switch):
- Free speech -- everyone sends messages freely; AI responds to them all together
- Turn-based -- one person at a time, host designates who goes next
Roles: Host (full control), Player (can send messages), Spectator (watch only).
When a world gets taken down
If a creator unpublishes their world, your existing sessions stay. You can read the history and export the chat log, but you can't send new messages.