@jose-ramos Looking good. Changing the color of the curtain seemed to make the make less busy which is good. I noticed that you put more detail on the train. I think less is more in this case as it draws your eye to it a bit much. Have you tried to give it a more wood based color? My focus is battling between the boy, train and mother atm (and also partially the highlight on the window frame), so it might help to try and suppress the color of the train, but make it longer so that it flows from behind the mother towards the boy if you get what I mean.
The top left part of the image is quite unimportant, so I would also try to tone down that area a little bit and maybe darken down the mother a bit as the light on her as i'm not seeing where the light is coming from. If you are in a dark room and are heavily backlit then the side facing away from the light would be quite dark. I think that this would help give this piece a touch more horror by not making it 100% obvious that it's his mother at first. Hope some of that helps (just spitting out thoughts and ideas 