You are in a house that is also a map. Nothing in it will tell you it is a quest. If you hear something, go and see.
ARROWS walk and climb · ENTER does the thing in front of you A second sibling can join at any time with W A S D and E The tide keeps its own time. Watch the moon.
The door opens inwards, which is not how it looked.
This is as far as the house goes, for now. Nobody has decided how the Keeper gets back.
Prototype. One house, one tide, two siblings on one keyboard. Toast, buttons and a pebble to begin with.