Mr. Sleepy Man is a 3D Platformer/ Adventure game about interacting with characters. Since Mr. Sleepy Man is sleeping all the time, he's not really in control of his actions. It's up to the player to shape Mr. Sleepy Man's sense of morality and decide whether this world is a sweet dream or a nightmare.
The main mechanic of Mr. Sleepy Man is the ability to interact with the world. This is a game where the consequences of your actions matter. If you decide to do something wrong or unethical, such as stealing the cash register from a local merchant, or breaking into a villager's home, the characters in this game will remember that and treat you differently.
Although there are many collectibles and platforming challenges for the player to discover in the non-linear open world of Mr. Sleepy Man, the focus is on the overall experience of the game, the little moments, the funny scenarios you happen to find yourself in.