Grandiose spectacles of horror are certainly impressive, but those don't usually keep me up at night. The scariest games I've played this year have been from smaller studios and even solo devs who've managed to piece together fantastic narratives, disturbing sequences, and spine chilling horror in compact form.
Mouthwashing was one of the best games I played all year and is now one of my favourite horror games of all time—which is pretty impressive for something I managed to finish in under two and a half hours.