Really liked the atmosphere, old-games-like style and music, but gameplay should be supplemented, i guess
I have some suggestions that can push you to some ideas, for example, some levels can be hidden in dark places and to see them and turn them off you will have to turn on some lights at first, or some objects like wardrobes or beds can block some levels (i also think that to do such things to levels they should look more natural to their surroundings). But that's just my thoughts
In general, i liked your game, it has its own way of attracting with atmosphere and visuals, so keep going