Super nice addition of the chair. Let's say the chair is actually the center of the puzzle. When and where to put the chair is the key to the puzzle. Sometimes i need to reuse the chair (which is expected before encountering it) and it is a nice twist essential to a puzzle (to figure out the blind spot and experience the aha moment).
I ll get this out of the way first: you have got the chair saying "space" on top of it, so i expected some in-game tutorials for "direction + space" to put it further, but you just put bob at the entrance to die so many times. You Monster (jk). Luckily you have put enough text outside the game to make it still taught to us players.
Just a tiny UX improvement: you try to convey that hiding in the chair is safe by turning black-and-white into black-and-darkgray. This greatly reduced the color contrast in the game. I would suggest black-and-midnightblue instead to maintain a higher contrast.
