Karin and the Hidden Lake is a short platformer about a girl who enters a forest to pick flowers during midsummer night. She is told this will reveal to her the man she will marry. To do that, she needs to pick the flowers by walking into them and ward off the shadows that surround her. When she does not progress fast enough the shadows will close in on her. There are also separate claw-shaped shadows that need to be avoided by ducking or jumping over them. She has no other means of defence.
The first part of the game is spent looking for the dress that will make her run faster and jump higher. It also features a section with a mirror lake, where he inner child is reflected and can be controlled separately. The developers made the game for the specific target group of women around the age of 35.