Liked the atmosphere, would love to see more of the story, and what happens to the character.
The injections were almost too common, I played through the whole thing being almost full on the injection vials, I get it was the first level and such but I never once experienced the "Out of control" element on my first run because I was just full up on Sanity the whole time.
Beyond that the jump I think was fine, but the left and right controls were a bit unresponsive, like ice physics all the time which made platforming feel harder than it probably should have.
Overall good job!