Those who leave a "1 star" and give the criticisms such as "This is a boring movie, it's too long, there's a lot of nothing, etc." Simply did not TRY to engage with the movie. I find Skinamarink unique in the fact that it requires the audience to visualize themselves in the shoes of the protagonists. Imagine being a child locked in a house with nothing but toys, cartoons, snacks, and your sister. No parents, no phone call [SPOILERS] most of the time. Then imagine the terrifying noises of "The Entity" that act as the eyes watching you from seemingly nowhere. Imagine being under the age of social comprehension and dealing with a living nightmare. It would be terrifying, and that's the feeling this movie is attempting to give the audience. This is not a movie you can watch mindlessly. This is not supposed to GIVE you anything. You do the work to make the movie good, and that's what makes it good. The movie plays into our primal fears of anticipation, anxiety, and the unknown. Allowing the atmosphere of the movie to settle on you is the most terrifying thing about the movie. The environment, reactions of the siblings, and the camera angles all give off an "uncanny" feeling, and that's exactly what you're supposed to feel.
This isn't supposed to be a story. It isn't supposed to be a conventional horror movie. It's analogue horror. One that instills fear based upon the audience's ability to visualize and bask in nostalgia.