Letters: A Written Adventure is a running and jumping literary puzzle where you write letters to your pen pal throughout the stages of your life. What's unique is that you physically explore each letter, using the lines as platforms and changing words to alter the meaning. You can throw words at the drawings to change them accordingly and unlock new areas and help you progress. It's an unusual game that blends platforming and letter-writing.

You play a young Swiss girl, Sarah, starting in the late 1990s, and working through the 2000s to the present day. By reading her letters, and later messages and texts, to her Russian pen pal Katya, you gain an understanding of her way of life; her passions, her woes, and more. You change the words written to change the flow of sentences, altering Sarah's life in often drastic ways, for better or for worse, making each story unique.

You run and jump along the lines and words of the letters. To progress you need to move and change words. While some of these changes are small, some are more drastic, making big impacts later on in Sarah's life.

Scattered throughout the letters are drawings and doodles, which you can throw words at to change. Throwing the word "nerd" at a drawing of a lighthouse turns it into Sauron's tower, Barad-dûr, from The Lord of the Rings.

While some changes are simply fun nods to pop culture, others are crucial to your progression through the story. For instance, you can make a doodle of a rat sit down to let you pass and get to the end of the letter. Or you need to find a way to regain strength and must find words hidden within other words, in this instance "rest" within "interest".

It's a wholly unique game, that blends traditional platforming mechanics with new and unusual ways to complete levels and offers a heartfelt and enticing story you can change as you play.