The HP bar gives an ominus feeling that the world isn't going to be as fun as that smile shows on the boy's face. xD
About the door and windows, there might be too much angling in the sides to portray perspective. This is most notable with the inner sides of the windows as they are compared with the door.
This is really giving me an Earthbound vibe. I have no idea if that's your intention, but it brings back a lot of good memories. :D