I think the biggest thing is that its just rather bland right now...more details and intricacies!
Um, I think you have some issues with the light source too: the chimney is casting a shadow (nothing else is--there's something else you should look into

) but the edges that are lit would mean the shadow (shadows, if you plan to add more) would come out the back, not the side. Either change which edges are lit, or move the shadow, or something.
This is pretty good though, for only your second pixel art--stay with it and you'll be sure to improve more than you though you could.
Good luck, and keep pixelling man.
