Oh, I guess I took for granted that the main character is female.
You should check out No Delivery! And if you like that, you might want to check out One Night at the Steeze on rpgmaker.net, which is sort of like a prototype of No Delivery.
The one game I can think of as being similar to these games is Lisa The Painful RPG by dingaling boy, although I'm not exactly sure if I'd call it horror. But it has the same perfect mix of dark, disturbing, and hilarious. And it's an all around great game with interesting battle mechanics. The music reminds me of the music in No Delivery, too. The prequel, Lisa The First, is more outright disturbing and sad (so perhaps more horror-like), but it's shorter and not as fleshed out and quite different from its sequel, gameplay wise.