I feel like cheap jumpscares, the kind that snap in out of nowhere with no player action or consequence... are usually terrible.

Jumpscares done with context and consequence can be great. In my game, for example, anomalies will only attack if you fail to scare them away in time, so the jump happens because you missed something, not because the game decided to shout at you. 

Another moment is when you’re operating the old film projector, you’re supposed to keep it running, and if you run out of film the lights go off and you only have sound. Creatures approaching, whispering, etc.. and the tension builds, and only then a jumpscare.

I’m curious what people think cause I want to make my jumpscares impactful not annoying in my game. Are jumpscares inherently cheap, or does it depend on context? Any favorite examples I could replicate (or bad ones to avoid), opinions, or ideas? If I like your ideas/opinion I'll add you in the credits :)

If anyone wants to see the kinds of jumpscares I mean, here’s what I'm talking about: https://deogen-games.itch.io/now-showing . Feedback welcome. Thank you!!

Not necessarily — but overusing them can. A well-timed jumpscare can be incredibly effective, especially when it builds on real tension. The problem is when games rely on constant loud noises instead of atmosphere, pacing, and psychological fear. That’s when it starts to feel cheap. The best horror games use jumpscares sparingly and focus more on mood and suspense.

Jumpscares are to horror, what slapstick is to humor.

It's a shortcut. Easily seen as bad writing or cheap. You need the right context for players to accept it or be awed by such things. The fnaf type games are all about jumscares. Just like you would expect slapstick in movies with the Marx Brothers, The Three Stooges or other names.

Any favorite examples I could replicate

I have a favorite example for a jumpscare, but you will not be able to replicate it, since your game is a fnaf type game and people will expect such scares.

Eternal Darkness, a horror game on Nintendo no less. The framework story had a character explore a mansion. In one of the rooms, there was a bathtub where you would have that jumpscare show it full of blood. In a literally jumpy camera zoom in. The rest of the game was about various horror topics and tropes, as it was the Lovecraftian type of horror story, but the tool of a jumpscare was bascially not used. It fit in with the sanity aspect, since the bathtub was shown to be empty aftewards.

I prefer less jumpscares and more general tension, but jumspcares themselves aren't a bad thing.
The problem becomes when they become so overused or they aren't done well that it becomes less effective to the players.

I don’t think jumpscares ruin a horror game. If they’re not overused or easy to see coming, they can actually make things way more tense and fun.