Here is an overview of the game, via its Steam page:

About

Snufkin: Melody of Moominvalley is a musical adventure game in which Snufkin needs to restore the harmony of Moominvalley, after a series of grotesque parks has appeared and ruined the valley’s natural balance. The game is an ambient and wholesome experience for both kids and adults, and combines open world-mechanics with puzzles, stealth, and melodic elements.

• Wander in Moominvalley – Explore the beautiful nature of the valley and beyond! Gain musical inspiration by finding secrets and solving puzzles on your path.
• Restore Harmony – The strict Park Keeper has built hideous parks everywhere and disrupted the natural balance of Moominvalley. Snufkin needs to help everyone bring the valley back to its beautiful origin.
• A Symphony of Characters – Get to know many of the beloved characters from Tove Jansson’s stories. If you already know and love the Moomins, you’ll likely meet your favorite character here, and if not—you’re in for a treat!

Key Features

• A cozy adventure game in a gorgeous storybook art style.
• Story-rich gameplay and charming characters to meet, each with their own charming stories to uncover and quests to solve, inspired by Tove Jansson’s work.
• Explore Moominvalley’s open world and solve musical and environmental puzzles along the way to uncover its secrets.
• Get the strict Park Keeper and his horrible parks out of Moominvalley with the help of your trusty harmonica, a bit of stealth, and the friends you’ll meet along the way.

Watch the announcement trailer below. View the first screenshots at the gallery.