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

About

Fling yourself into a mountain climbing adventure!

Surmount is a free-flowing, physics-based platforming adventure where you’ll experience the joys of mountain climbing. Make your perilous ascent through the various handcrafted and procedurally generated challenges of Mount Om, all the while following a silly story with eccentric folks along the way. Master your own unique style of climbing either alone or with a friend, upgrade and customize your climber to stand a better chance, and maybe just maybe, you’ll be the first ever to reach the top!

Key Features

• An approachable physics based climbing system that is endlessly replayable and not overly punishing.
• A mix of handmade levels and large procedurally generated areas to overcome.
• On your way to the top of Mount Om, you’ll meet a variety of eccentric characters, all with their own reason to journey to the top (camping).
• Unlock a variety of permanent and equipable items that will boost your stats.
• Be the most fashionable climber out there by customizing your character’s look.
• Play alone or tethered to a friend in local cooperative play.

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

Announce Trailer