While Nara's Nook is an opensim grid where you need an additional viewer and an account to log in,
this version (written in Unity3d) can either be called directly via its WebGL instance
or be downloaded to your PC and run locally (which should give a smoother experience due to higher frame rates).
You can choose an avatar and a display name on the launcher screen, then hit play and connect to the scene.
In move mode you can move around using either the "wasd" or arrow keys.
Hit Space key to jump
Use the scroll wheel to zoom in and out.
If you click your right mouse button, you switch to camera control mode.
The mouse pointer becomes invisible, moving the mouse controls your camera and you can rotate it around your character.
Your character now moves relative to the camera direction.
Right clicking again switches back to move mode.
This also turns the avatar, so it faces the camera direction.
Hitting the Return key or clicking the chat button opens a chat window so you can chat with other people in this scene.
You have to open your chat window to see what others are typing.
While you are in chat mode you can't move your character.
To exit chat mode hit the Escape key or click the chat button.
When you approach a chair it shows you a message that you can sit down using the "e" key.
(in this test version i made some chairs "phantom" so you can run into them and some others "solid" so you bump into them)
The "f" key lets you fly. In this mode the character moves relative to the camera direction,
i.e. you have to be in camera control mode (right click) and move your mouse "under" your char to fly up.
While you are in chat mode you can use some commands by starting the line with a slash /
To see a list of the currently implemented commands use /? or /help