Yume Nikki is without a doubt my favorite video game. I bet I'm probably the only person here who knows about it because it's a cult classic RPG Maker game from 2004. In Yume Nikki, you play as a girl named Madotsuki who can't really go anywhere outside her room for whatever reason. The only things you can do are play NASU, a depressing high score game, or sleep. Once you fall asleep, you get to the main core: you get to explore around 50 unique dream worlds in search of 24 effects, items that change your appearance. Some worlds are very unnerving, some more cartoony, and some even play like a NES game. What's great about this game is it's atmosphere, it really gives off a lonely vibe, all the music is five-second loops (they're great though), and there is no dialogue. Most of the game is just exploring and finding cool stuff. It was made with RPG Maker, but is nothing like one. I wouldn't recommend it to everyone, due to how different it is, but if what I described sounds cool, then check if out (it's free on Steam)!
