Less emphasis on jump scares

That's a good point. The "scary" genre spans a really wide range of games. Might help if OP lists some games that they particularly liked, and maybe any that aren't quite what they're looking for.

Consider some games that might be considered scary (not selecting these as the "scariest" or 2D, just examples of how broad a variety of scary games might be):

• Gone Home. There's no killing, no monsters. But it's got a spooky ambience -- I mean, you're wandering around an house where people are missing, trying to understand what happened. I don't know if I'd call it a horror game, but there are definitely people who might call it "scary". I felt tense while playing it.

• World of Horror. This has no shortage of gore, but its graphics are 1-bit and low-resolution.

• White Night. That's also black-and-white, but entirely-different, derives most of the scary factor from ambience and limited visibility. No gore. You can definitely die, though.

• The Lurking Horror. Just text.

• Resident Evil: Village. High-end, realistic graphics.

• Super Lone Survivor. 2D, color pixel art with 3d hardware effects.

• I Have No Mouth, And I Must Scream. A core element of the game's horror is that the characters cannot die.

• Among the Sleep. You're a mostly-helpless toddler.

• F.E.A.R. 2: Project Origin. You're a decidedly not-helpless special forces operator, lots of jumpscares.

• The Forest. Open-world, not driven by a story.

• Inscryption. A deckbuilder.