Not exactly what you’re asking for, but Subnautica slowly builds on a primal fear without resorting to jump scares. It’s increasingly unsettling and you start finding excuses to just stay in your habitat to decorate instead of going outside.

Life is strange has elements of it (think Butterfly Effect: the game) during parts of the game, although it gets pretty explicit rather than subtle.

Oxenfree also has elements of it, with people behaving weirdly etc. But it also mostly gets fairly explicit. Still, no jumpscares.