Simple but effective. This builds tension really well. The camera essentially acting as a timer makes it really stressful whenever you mess up in the platformer. Keeping the sleepwalker at bay is really simple but the constant choice of how you need to split your attention is engaging.
I beat the game on my second attempt after running out of flashes which was pretty intense. On my first attempt I ran out of flashes and I was on the first level with the dark background so I figured it wasn't the last level and checked out of the game before the jump scare I knew was coming.
But other than that one small moment this was really well done and I enjoyed this a lot,