Here is an overview of the game, via Yokaze:

About

Fox and Frog Travelers: The Demon of Adashino Island is a 3D action adventure game with a Japanese-inspired atmosphere. You will play as Fox, a girl who finds herself on Adashino Island and starts traveling with Frog. Torii gates, food stall lanterns, and neon signs give light and color to the island. Something is lurking in the shadows, inching ever closer… Fox and Frog Travelers: The Demon of Adashino Island is currently under development by Rias, an illustrator and concept artist that came up with the idea for it based on one of his illustrations. The story of Fox and Frog’s long journey through the night is planned for release in a few years.

Story

Modern Japan.

A shrine tucked away in the back alley of a big city.

A fox lived there.

One night, she’s caught in a massive power outage.

Wandering around in the darkness with his friend, Frog, in search of light.

Suddenly, they drifted to a strange island.

The island is called “Adashino Island.”

There, they meet…

A town covered in countless dazzling lights.

People seeking the light and flocking to it.

And then…

…were ferocious demons that would make your hair stand on your whole body.

Watch a trailer below. View a set of screenshots at the gallery.