The trick (albeit difficult) is to be very subtle about it, maybe a quick emote from the main character "I shouldn't be here" or some environmental design that

The trick (albeit difficult) is to be very subtle about it, maybe a quick emote from the main character "I shouldn't be here" or some environmental design that guides the player. Valve is doing an amazing job there usually, Super Giant Games as well). Other game devs slap you over the head with it, with markers, popups, and whatnot and don't even let the player do any discovery, an endless tutorial.